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.

South African here, I seem to be unable to connect through any wifi networks that use mweb, haven't gotten a chance to try any others though and certainly wont until I have another holiday.

>>15
It could also just have been a whim.

I only have trouble posting though so it isn't all doom and gloom.

Kinda sucks regardless...