Receive hacking threat

[tafreeh]

there was an idiot on my forum today advertising his forum, so mod banned him and then he threat'em that he will take this forum down.

and then my server went down twice, and i receive more than 40 email regarding Database Error
here is the sample of one

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (11)
/home/user/public_html/includes/class_core.php on line 311

MySQL Error :
Error Number :
Request Date : Tuesday, September 15th 2009 @ 07:56:10 AM
Error Date : Tuesday, September 15th 2009 @ 07:56:24 AM
Script : http://www.tafreehmela.com/
Referrer :
IP Address : 119.***.**.***
Username :
Classname : vB_Database
MySQL Version :

any suggestion from any expert? i wanna know wat did he do, and how do i keep myself safe from these $$%$%#$%$

[jazz_aaf]

Coincidence i guess. It is just that your mysql was not reachable by your webserver for a moment.

[Lynne]

I'd say it's coincidence. See this page for the causes of this error: http://www.vbulletin.com/docs/html/cantconnect