It's so easy to do things online anonymously, but there's no guarantee of anonymity. I think many people believe there is a guarantee.
As far as I know, there's no law against mentioning the identity of a blog visitor, but usually there's no point in doing that. I've only "outed" visitors to this blog on a few occasions. Primarily due to offensive search-string messages I'd received (it's a long story.) I thought it was better if people sending the messages knew they actually were not anonymous, figuring it would tend to moderate the offensiveness of the messages.
Clearly there are many risks with people acting under cover of anonymity.
Which brings us to Anonymous.
The videos of Anonymous are often pretty creepy:
However, Scientology is also creepy:
Gawker's article about Scientology's battle to surpress the above video.
Certainly Scientology's Fair Game policy identifies it as a fundamentally lawless organization. So Scientology is pretty much the perfect target of Anonymous.
I think Scientology is a worthy target of Anonymous. But what if Anonymous decided to target a less evil organization?
Jerry O'Connell paraody of the Cruise video.