Just a suggestion for admins, Why don't implement a simple captcha system? Like add 3 + 6 to post to for Newbies - Full Members or may be even include Hero Members too, It should greatly reduce spamming.
This won't help. Most of the spam is due to humans copy-pasting or typing nonsense for signature campaigns.
Adding a captcha to post won't deter them.
Well if that's the case, May be use some sort of plagiarism checking service, A Quick Google search revealed quite a few services which offered api's but cost upwards of $900 per month, And i believe instead of ip's being banned, Why not ban the systems, I think Chrome and all most All Browser have some sort of Unique Device ID, Why not store those and ban whole systems. This will reduce the costs in the long run.
The implementation of scripts to check all the posts being made in this forum might be difficult.
IPs are not banned, Units of evil just get added to them. It is still possible to register/post using those IPs, if you pay a small fee.