Deep,
Such incidents are most of the time
rumours/hoaxes, nothing to worry about them.
Our servers are well equipped to fight against such hack attempts & to keep them at bay. We have various tools (
firewalls) running on our servers to monitor such events. None of our servers have been yet hacked,
but unfortunately (as hairyfreak said) few website hostings are hacked due to insecure permissions set on files by their owners/webadmins.
If you received any such email from the hackers, please have it forwarded to our support dept.