"There have been a lot of recent spam attacks on moderators of big communities. The spammers will hack into a moderators journal, delete all the other moderators and post in the community a link to a virus. We would like to warn you not to click any strange links. We would never direct you to a website outside of LiveJournal. To check the link, please use your mouse to hover above the link before clicking it. If it says something like "tinyurl" or anything other than LiveJournal, do not click the link because it could be a virus."
PS - Oh yeah, I'm a mod, in case you're wondering. Yay hooray.