Several people, by no direct fault of their own, have become spammers on Facebook. The problem has gotten a bit out of hand. It's simple: they see a link a friend posts on their page, they click it, and within seconds the same link with the same comment is posted at least a dozen other people. It can be stopped by removing the post without clicking the link. The X is found in the top right-hand corner of the post. Make sure to click "Remove Post..." instead of the other options, as they may cause your friend problems in the future. It's highlighted below, in blue, so you can't miss it.
There are two big offenders in the spamming: Osama and a link to show you what you'll look like when you're older. There are obvious reasons why people think these are genuine links: everyone wants clarification that Osama is dead and lots of people are amused enough by images to click the second link.
So far I can't see any major problems with these links except that they spam the heck out of as many people as the link possibly can. The more friends you have, the more people will get spammed. Simple as that.
The biggest issue seems to be that they are just annoying links, posted dozens of times all over Facebook. There may be more in the future, but for now these are the two I am familiar with. Before the admins at Facebook can get around to fixing this problem, users can prevent themselves becoming the centre for spam by simply removing these posts from their pages; even if you don't click it, your friend might. Hopefully the tide of spam will stop within a few days if everyone follows this simple advice.