Web****** need to wake up and to install probably a couple mods that will fight against spamming.
Captcha by registering, captcha by first post for new member, disabling of posting links until you have 5 post, extra simple question (required to answer) by registering etc... are just for example that will reduce spamming this ***rd for **&#*7;.
It is for sure seriously problem and i know that web****** of some ***rd decided to close their ***rd because they feel helpless against spam.

btw

Posting ip address or hostnames will not help against spamming.As i told you they even do not look into ***rds and do not care because they use automated forum posting tools.That's are so advanced tools that they can read captcha and do many other things but web****** still can do a lot to prevent spamming.