ISP blocked due to abuse?

Well, it seems today that I'm now unable to post anything over at the 4chan imageboards, otherwise I get this message:
"Posting from your ISP has been blocked due to abuse. [More Info]"
I can still browse the site, all the images and threads load fine, I just can't post. What gives? I've never posted spam or porn.

>>895
This thread is going to reach 3 years old and moot needs to know about this.

He needs to at least create a way for the innocent people to bypass or be immune to this block. At this rate every ISP will be blocked, what happened to IP range bans? There's no way to bypass those as far as im concerned. Why not range IP ban the shitheads?