I've been having the weirdest problem with my browsers. My default browser is Google Chrome, which has a cool feature: Type a word or term in the URL window, and it automatically takes you to Google.
But when I type in a term, I often get an error message. So I type in www.google.com, and it's dead, too. Facebook is a problem, too; sometimes I can access it, and sometimes I can't.
However, this problem might not be browser specific; when I switch browsers, I get the same problem on at least some occasions.
I'm using a Mac, so I doubt that it's a virus. The problem is intermittent; if I wait a while and try again, I can use Google and Facebook. But what is it that kills those sites repeatedly?