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.

>>234
É por cause desse mancebo que não podemos postar nada no 4chan? É que são ainda um grande número de ISPs portugueses bloqueados. E sofrem os /b/tards portugueses por causa de um puto que nem cona viu ainda. Pena é que foda a vida a quem não a viu também e tinha o 4chan para compensar a sua virgindade...
Havia de ser posto numa cela com o bibi, Carlos Cruz & companhia a ganhar 40 cêntimos por enrabadela para ver se ainda continuava a ser ganancioso.

BTW: I've sent a message to MrVacBob like >>231 said, but the guy didn't even bothered to answer it. It seems that he unbans individuals who fuck themsleves but want a second chance, but people like us who follow all moral and internet rules don't get another opportunity. Like everything in life it's always the honest guys who get fucked up.
Does anyone know anything that can be done? Over a year now with 4chan blocked, and I haven't found any proxy that works.