This has been going on since the
$250 cookie recipe and before.
People
want to believe they're smart enough, plugged-in enough, subversive enough, or lucky enough to get one over on "the man." People want to be the special unique flower, and the internet is the perfect place for insecure people to present themselves as one.
More than that, though, people want to be the first to contribute something new to their group. They want to be
recognized, and by and large most people's internet contacts are universally supportive. It's never been easier to gather groups of people who will support whatever you say, regardless of whether you're right or wrong, and all that feeds on itself. In a world where replacing a "friend" is a matter of a couple of penis clicks, it's easy to want to ingratiate yourself to as many people as you can. It's the opposite of trolling but it comes from the same insecure place that we all ultimately have.
In a network of this sort, fact-checking isn't appreciated; it's an active act of rejection. People don't change their ways when called out about this because
you are the one in the wrong for pointing out that this GREAT NEW THING isn't great or new. They're used to a world where communication is costly, and where people didn't waste it on things they didn't know were true.
I was going to end with the thought that someday, someone will actually invent a for-real c*ck enlarging device and they'll never be able to market it, but given the number of TV ads for ED drugs I'm gonna guess that someone will eventually listen...