The library
Resources.
Practical articles about patents, patent trolls, and patent defense. Written for people who got sued, not for law students. 40 pieces and growing.
Tool · Demand letter analyzer
Got a patent demand letter?
Paste it. We extract the asserted patents, characterize the asserter, flag validity vulnerabilities, and draft a sample response your attorney can review.
Analyze a letter
Tool · Patent Quiz
Test what you know.
10 questions, about 3 minutes. Patents, NPEs, post-grant review, prior art, obviousness, and the cost asymmetry that makes the troll business model work. Instant scoring with explanations.
Take the quiz
Foundations
What a patent actually is, what it isn't, and the bedrock concepts every defendant should know.
What is a patent?
A patent is a 20-year government-granted monopoly on an invention. We cover what patents do, what they don't do, and why bad ones cause so much harm.
4 min read
How to read a patent claim
A patent's claims are the only part that legally matters. We walk through how to read one, what the magic words mean, and how to spot the weaknesses.
5 min read
Patent term and expiration
How long a US patent actually lasts — 20 years from the earliest non-provisional filing, plus the maintenance fees, term adjustments (PTA), term extensions (PTE), and family-priority quirks that move the date in either direction.
4 min read
Patent law glossary
Quick-reference definitions for every patent-law term of art used across the site. Each entry links to the dedicated article when one exists, and articles deep-link into individual entries via /resources/glossary#term.
8 min read
Getting a patent
The USPTO process, costs, timelines, and the trade-offs at every step.
Patent reviews
The post-grant invalidity tools — IPR, PGR, and reexamination — and when to use each.
Patent reviews: IPR, PGR, and reexamination
Suing in district court costs $3-5M. The USPTO's post-grant review system invalidates patents for $200-500k. We cover IPR, PGR, and ex parte reexamination — when to use each, and the estoppel traps.
5 min read
IPR estoppel: the trade-off behind the cheapest invalidity tool
Inter Partes Review is the most cost-effective way to kill a weak patent — but the trade-off is estoppel. If your IPR fails on a final written decision, you can't later raise in district court any prior-art ground you raised "or reasonably could have raised." The mechanics, the workarounds, and how to file without burning your fallback defenses.
5 min read
Cost of Inter Partes Review (IPR): a 2026 breakdown
What an IPR actually costs — USPTO fees, attorney fees, expert costs, and hearing expenses. Plus when the spend pays, when it doesn't, and how to share the bill with co-defendants.
9 min read
Patent trolls
Non-practicing entities, the economics that let them work, and the structural fixes that bite.
What is a patent troll?
A patent troll is a company whose business is suing other companies. We cover the NPE business model, the cost asymmetry that makes it work, and the structural fixes that bite back.
6 min read
How patent trolls operate (and why the business model works)
The deep dive on patent troll operations — corporate structure, patent acquisition pipeline, assertion campaigns, litigation finance, defensive aggregators, and what's changed over the past twenty years.
9 min read
Examples of NPE shell companies: how patent trolls structure their entities
A field guide to non-practicing entity shell structures — well-documented examples (Acacia, Lumen View, MPHJ, Lodsys), why shells exist, and what they tell defendants about settlement leverage.
10 min read
Most-litigated US patents: 12 patents that defined the patent troll era
A field guide to the most-asserted, most-notorious patents in modern US litigation — Shipping & Transit, MPHJ, Personal Audio, VirnetX, Uniloc, and more. Each entry: campaign size, defendants, how it ended.
14 min read
Anatomy of a shakedown: how a patent troll campaign actually works
Step-by-step pictorial guide to the patent-troll business model — patent acquisition, target list, demand letter wave, the response funnel, the litigation pressure cooker, and the settlement curve. Once you see the volume-based extortion scheme, you stop fighting the wrong opponent.
9 min read
The Patent Scam (2017): a documentary on the patent troll industry
Austin Meyer's 2017 documentary puts cameras in front of the small businesses, engineers, and inventors getting picked off by patent trolls. The most accessible piece of journalism on the patent troll problem — and now free to watch on YouTube.
3 min read
Defenses
Invalidity, non-infringement, and the procedural lifecycle defendants navigate.
Prior art and § 102 novelty
35 U.S.C. § 102 is the bedrock of patent invalidity. If the invention was already public, the patent is invalid. We cover what counts as prior art, the on-sale bar, and how to build a § 102 defense.
5 min read
Obviousness under § 103
When prior art doesn't anticipate exactly, § 103 obviousness is the workhorse defense. We cover the KSR framework, motivation to combine, and how to argue obviousness in court and at the PTAB.
5 min read
Prior-art research, old way vs new way — a side-by-side comparison
What used to take a senior associate at a white-shoe firm 80 hours and $80,000 now takes an LLM with web-search grounding three minutes and roughly a dollar in API costs. The full breakdown — what each method searches, what it produces, where AI stops and human judgment starts.
6 min read
Finding prior art with free tools: Google Patents, Lens, Espacenet, and more
A defendant's hands-on guide to free prior art search. Which tool to use first, how to translate claim language into queries, how to read citation graphs, how to find non-patent literature, and how to know when to stop and call counsel.
12 min read
AI prior art search tools: a 2026 buyer's guide for defendants
How AI prior art search tools work, what they're good at, what they miss, and how to use them to build a credible invalidity case for under $5,000.
8 min read
How to read a patent claim chart
A claim chart is the plaintiff's element-by-element infringement story. Most charts are thinner than they look. Here's how to read one, where the weak spots usually hide, and how to convert a bad chart into real defense leverage.
10 min read
The patent litigation lifecycle
A patent lawsuit looks chaotic from the outside. Inside, it's a sequence of well-defined stages with predictable cost spikes, decision points, and exit ramps. The procedural map every defendant should have on their wall.
6 min read
District court vs. PTAB: where to fight a patent challenge
The two forums where patent invalidity gets decided — Article III district court and the USPTO PTAB — have different burdens, different timelines, different costs, and different estoppel consequences. How defendants choose, when to do both, and when one forecloses the other.
11 min read
Non-Practicing Entity (NPE) lawsuit defense: a defendant's playbook
How to defend a patent infringement lawsuit brought by a non-practicing entity — venue moves, Alice motions, IPR strategy, joint defense economics, and fee shifting.
11 min read
Joint defense groups: economics, formation, and the privilege framework
How co-defendants pool defense costs in a multi-defendant patent case. The common-interest privilege framework, the JDG agreement, cost allocation models, lead-counsel governance, IPR sharing, and the free-rider problem.
13 min read
Declaratory judgment actions: when to flip the table on a patent troll
A declaratory judgment action lets a defendant sue first — asking a court to declare a patent invalid or not infringed before the patent holder files. Used right, it flips venue and resets the asymmetry. Used wrong, it lights $500K on fire and accelerates a fight that wasn't going to happen.
10 min read
§ 285 attorney-fee shifting in practice
Attorneys' fees in U.S. patent litigation usually fall on whoever paid them. The exception — 35 U.S.C. § 285 — lets prevailing defendants recover fees in 'exceptional cases'. The procedural mechanics, when it bites, and what defendants actually recover.
6 min read
Landmark cases
The Supreme Court rulings every patent defendant ends up citing — Alice, KSR, Octane, eBay.
Alice Corp. v. CLS Bank International (2014)
The unanimous Supreme Court decision that codified the modern abstract-idea framework under 35 U.S.C. § 101. Alice is the bedrock § 101 case — the most-cited tool defendants have for invalidating software and business-method patents.
4 min read
Bilski v. Kappos (2010)
The Supreme Court decision that opened the modern § 101 era. Bilski rejected the Federal Circuit's machine-or-transformation test as the sole patent-eligibility framework and held that a method for hedging risk in commodities trading was an unpatentable abstract idea — setting the stage for Mayo and Alice.
4 min read
eBay Inc. v. MercExchange (2006)
The Supreme Court ruling that ended the Federal Circuit's automatic-injunction rule in patent cases. After eBay, a non-practicing entity rarely gets an injunction — making NPE litigation primarily a money game.
4 min read
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (2002)
The Supreme Court decision that calibrated prosecution history estoppel against the doctrine of equivalents. A narrowing claim amendment creates a presumption that the patentee surrendered the territory between the original and amended claim — but the presumption is rebuttable on three narrow grounds.
5 min read
KSR International v. Teleflex (2007)
The Supreme Court decision that flexibilized the obviousness test under 35 U.S.C. § 103. KSR replaced the rigid TSM framework with a holistic analysis that the PTAB now uses reflexively.
5 min read
Lumen View v. FindTheBest (2013-2016): when a defendant fought back, the troll paid
The 2013-2016 case that became the template for post-Octane fee-shifting against patent trolls. US Patent 8,069,073 invalidated under § 101 in Nov 2013, attorneys' fees doubled in Oct 2014 as a deterrent against predatory NPE conduct. The running example throughout this site.
6 min read
Markman v. Westview Instruments, Inc. (1996)
The Supreme Court decision that put claim construction in the judge's hands, not the jury's. Markman created the pretrial 'Markman hearing' that decides most patent cases in all but name — the construction the court issues governs infringement and validity for the rest of the case.
5 min read
Mayo Collaborative Services v. Prometheus Laboratories (2012)
The unanimous Supreme Court decision that revived § 101 as a meaningful patent-eligibility limit. Mayo gave us the two-step test for natural laws and laid the groundwork that Alice Corp. v. CLS Bank would extend to abstract ideas two years later.
4 min read
Octane Fitness v. ICON Health & Fitness (2014)
The Supreme Court decision that lowered the bar for prevailing defendants to recover attorneys' fees from patent plaintiffs. Octane is the structural lever that occasionally turns a troll's economic model upside down.
5 min read
TC Heartland LLC v. Kraft Foods Group Brands LLC (2017)
The Supreme Court decision that pulled patent venue back from the Federal Circuit's expansive reading of 28 U.S.C. § 1400(b). For domestic corporations, 'resides' means only the state of incorporation — overnight ending the Eastern District of Texas hegemony and shifting patent litigation to the District of Delaware.
5 min read
Policy & reform
The statutory framework — the America Invents Act and the structural reforms that gave defendants modern tools.
Practical guides
What to do, in order, when a patent matter actually lands on your desk.
What to do if you get a patent demand letter
A patent demand letter usually arrives without warning and demands a quick response. Here's what to do, what not to do, and what your real options are — in order.
6 min read
How to respond to a patent troll demand letter
A practical guide to responding to demand letters from non-practicing entities (NPEs). What to send, what to refuse, and how to make the troll's economics work against them.
8 min read
The first 30 days after a patent infringement complaint
A complaint just hit your front desk. The clocks are running. Here's what happens day by day in the first month — litigation hold, answer deadlines, venue analysis, IPR window, joint defense outreach — and the decisions you have to make in order.
11 min read