As many as 60% of online profiles are fake.
(This is especially common on dating sites, where member's profiles often feature stock images found on the internet, sometimes of pornography actresses or models.
But it's not always the person featured in the profile who lies. An Englishman was featured in a fake gay profile by a so called friend, but he had the last laugh as he was awarded $45,000 in a libel case he brought against the former friend.
Of course, I would never lie on my profile.)