Back to the subject at hand -
In his book Beaver Street, Robert Rosen provides rare documentation of ascam involving High Society magazine, in which users were asked to verify their age via credit card information to access an ostensibly free tour and then auto-billed $60 a month.
Not that business practices ranging from disingenuous to fraudulent are unique to pornography.
https://hackerfall.com/story/tubes-vs-torrents-the-ethics-of-piracy
A good read.