What is "patent troll"

n. (context informal derogatory English) A person, company, etc. that holds and enforces patents in an aggressive and opportunistic manner, often with no intention of marketing or promoting the subject of the patent.

In pejorative usage, a patent troll is a person or company that attempts to enforce patent rights against accused infringers far beyond the patent's actual value or contribution to the prior art. Patent trolls often do not manufacture products or supply services based upon the patents in question. However, some entities which do not practice their asserted patent may not be considered "patent trolls" when they license their patented technologies on reasonable terms in advance. Other related terms include patent holding company (PHC), patent assertion entity (PAE), and non-practicing entity (NPE), which may or may not be considered a "patent troll" depending on the position they are taking and the perception of that position by the public.

Patent trolling has been less of a problem in Europe than in the U.S. because Europe has a loser pays costs regime. In contrast, the U.S. generally used the so-called American rule, providing that each party is responsible for paying its own attorney's fees, until U.S. Supreme Court decided Octane Fitness, LLC v. ICON Health & Fitness, Inc. on April 29, 2014.