Letraset had an experiment some twenty years ago which drove users crazy. To protect their software, they had programmed the fonts to be installed only 5 times. After that they were, like, dead. I remember FontShop had the occasional hysterical customer saying “I’ve installed it 4 times already and it’s still not working, I’ve only got one chance left!” Needless to say, the experiment was never taken up in the industry.
Does anybody have more precise information about this technology, and did this font format have a specific name?