I found this in my error log today:
[Wed Aug 17 14:50:26 2011] [error] [client 220.127.116.11] PHP Warning: opendir(/home/<My username>) [<a href='function.opendir'>function.opendir</a>]: failed to open dir: Permission denied in /home/<Another username>/public_html/wp-config.php(2119) : eval()'d code on line 3
It looks like another account on my server tried to access my home folder. I don't use WordPress myself. Is this a problem? How does another user know my server username in the first place?