forbidden access

Ok deleting alot of PMs from my inbox one after another and all of a sudden i get a white page with forbidden access. your computer is generating requests that look like melware and viruses attacks. if you are not a melware attacker accept our apologies and click here to continue browsing. your security system is a little paranoid isn't it.

WE were getting quite a lot of spam, so we needed something to prevent it.
Did the "I am a human" link work for you?

yes. but how is deleting pms one after another spam. this was before i found the button that lets me delete them all at once.

Of course this is not spam
The software scans IPs with use the site excessively and block them until they prove they are a human being.
People don't usually get this page, but from time to time there is a false positive caught on the system.