This applies to everyone, not just Twitter users. See what happens when you start to type either your username/e-mail or password into the text entry fields:
http://www.ismytwitterpasswordsecure.com/
Here's the source article, which is worth reading:
Beware Twitter "password check" sites - there are fakes, and there are fake fakes!
http://www.ismytwitterpasswordsecure.com/
Here's the source article, which is worth reading:
Beware Twitter "password check" sites - there are fakes, and there are fake fakes!