Keep on the lookout for anything suspicious when browsing websites because it looks like there is a new virus/trojan out that is causing havoc. This Yahoo! News story gives more insight to the virus and what it is doing. Another one focuses on the financial implications.
The way it looks now is that this virus is shutting sites down and installing malicious code on a users computer to get bank account numbers, credit card info, etc.
If you go to a site and are asked to download anything before continuing, do not do it. This thing is nasty and I haven’t seen any updates by Symantec as of yet.