From the summer of 2002, an example of Dubious Patent Usage:
So apparently British Telecom was combing through its archives and found something bearing U.S. patent number 4,873,662 which, BT thought, was the basis for the hyperlink. Visions of dollar signs (what with sterling giving way to the euro, doncha know) danced in their heads, and they hit up more than a dozen ISPs for licensing fees. When said ISPs told BT to go pound sand, BT decided to make a test case out of one of them.
The ISP in question asked for summary judgment while laughing out loud, and got it.
That ISP was Prodigy Internet. Less than a year later, its parent company, SBC (now AT&T), tried basically the same stunt:
SBC Communications, whose main contribution to the Internet up to this point has been putting perennial money-loser Prodigy out of its misery, is now claiming a patent on the invention of HTML frames.
Given the general opinion of HTML frames at the time, this was like applying for a job as sous chef and naming Jeffrey Dahmer as a reference.
Meanwhile, also around the turn of the century, an Australian bloke was trying to make a point:
Way back in 2001, the Australian patent office awarded a man named John Keogh “Innovation Patent #2001100012” for his “circular transportation facilitation device.” Or what people who don’t work in a government office would call a “wheel.”
Mr. Keogh submitted his patent request as a way of illustrating that he thought the office had relaxed its standards a bit too much. He never tried to collect any money from people using wheels. So it turns out that the office recently revoked his patent, just more than a decade after issuing it.
Then again, since Mr Keogh did not in fact try to hit up unsuspecting wheel users for royalties, he would presumably not be considered a patent troll. Had he been an American, he’d probably have been looking for a courtroom in, say, east Texas, and a test case with a defendant with deep(ish) pockets.