If you have yourself a Nokia S60 device you should be aware of a bug named the “Curse of Silence”.
With a name like that you’ve gotta pay attention! The hacker sends you a text message with a unique 32 character code that blocks and rejects all incoming messages (text and e-mail). The only way to fix it is a hard reset of your device.
Just in case this does happen to you make sure your info is backed up. Here is a video of what happens: