So apparently twitter was hacked and in the process many accounts were compromised. The simple fix is to reset your password but the hackers were able to compromise the server that hosts all of Twitter’s stylesheets so that changing your password is damn near impossible.
(NB: technically it was a DNS hack that redirected traffic to a different server entirely)
The fix. If you’re on a Mac/Linux enter the following into your /etc/hosts file:
(you should remove this later when twitter fixes the problem).
Go ahead and reset your password.
Important: you should also revoke access to all of your applications in case one of those was the entry point through which your account was accessed (ie; it may not have been your password it may have been an authorized app).
To revoke access, go into your settings, click “Apps” and click the Revoke Access button next to all of your apps.