A JS bug in Twitter’s code redirects visitors to user @false.
Here’s how it works:
1) Go to search.twitter.com but make sure you’re logged out of Twitter
2) Enter a search query (example: 42)
3) You should land on the ‘Most relevant’ tab. Click on ‘All Tweets’ instead.
4) Now click on ‘Tweets with links’ and see what happens.
(Bug discovered by Mallikarjun Reddy and sent to Twitter)