No thumbnails on 4chan

Hi guys.
I don't know why, but none of the thumbnails on any of the boards work. I can click on the thumbnail and open the full size image though.
This just happened overnight. Have no idea how.

Also, 99% I can't post anything. After I hit reply, I just get bumped to the main page. wtf?

(btw, I tried this in both Internet Explorer and Firefox)
HALP.

I found out the cause. Some routers think the thumbnails are a DDoS from 4Chan so the firewall blocks them.