I love the Daily Show's commentary on the media, and this is definitely a good one. I'm tired of receiving the odd email forward, and hearing people taking such as actual fact. Few people question them.
The fact that such rumors end up on the news media really doesn't help.
Most of the work I do is for an educational institution (see Math2Success, and a lot of the time, even as an editor, I check the math. I'm not a math expert. I could easily just put pieces together based on what we're given, but no - I fix it in graphics. I make sure what we put out there is real math, and 2 + 2 doesn't add up to 5.
This being said, there are several internet rumors against McCain (my personal favorite being that one spread in 2000, about McCain's lack of environmental policy - no not the illegitimate black child - that rumor was just cheap).
Memes have a way of spreading influence:
Which is to call a spade a spade, really.
Gossip and rumor have been elevated to a new state with the internet, and it requires better discernment, and education in critical thinking.