https://arstechnica.com/tech-policy/2019/08/patent-troll-sues-over-patent-troll-label-loses/ > Automated Transactions Limited (ATL) is a small firm known for its aggressive enforcement of broad patents related to automated teller machines. Numerous critics labeled ATL a patent troll, and in 2016 the firm sued several of them in New Hampshire state courts, arguing that the label was defamatory. > On Friday, the New Hampshire Supreme Court dismissed ATL's lawsuit. To win a libel lawsuit, a plaintiff has to prove that a statement is both false and defamatory. A statement of opinion can't be proven false, and hence can't be the basis for a libel claim. New Hampshire's Supreme Court ruled that calling someone a "troll" was just such a statement of opinion—and so someone can't be liable for calling someone a troll.