Hasn't YouTube always seemed too good to be true — all those video clips, for free? We must be getting away with something. That's why rumors about a new YouTube virus have spread so far, so fast.

Some people viewing YouTube videos have gotten an alert saying antivirus software has detected a computer virus called Actns/Swif.T. That virus is real enough; it redirects people to a website which then installs a piece of hostile software deceivingly called Antivirus 2009. The software is actually spyware, and notoriously annoying to remove.

But YouTube is not actually infected with a virus, it turns out. Instead, out-of-date antivirus software is mislabeling YouTube clips as a threat.

Panic over, right? No. The video format YouTube uses, Flash, has proven insecure before. YouTube processes users' video files and generates its own Flash files, so it's unlikely that YouTube would host hostile code — but never say never. As people spend more time on video sites and social networks like MySpace and Facebook, they increasingly become targets for virus creators.

The bigger problem here is figuring out whom to trust. Outdated virus-detection software, or the websites they're labeling as dangerous? Blogs which report new viral threats, or the ones that debunk them? Software which labels itself "Antivirus" but actually infects your computer? We're going deep down the rabbit hole, and I don't think Keanu Reeves is waiting for us on the other end.