Chat disabled when logged off

Hi! I'd like to know why I can't chat with anyone when I'm logged off? I can't write anything (box for writing is disabled) - I can only use some default phrases integrated in chat (HI, GL, HF, U2,...) but if I log in with my account then chat box is enabled and I can write anything. What's happening?!
- I also noticed that a guy who I was playing with (who was also logged off) was able to write me something (he asked me something) but I couldn't respond - so why is he able to write me when logged off and I'm not?!

I'm pretty sure anonymous people cant chat anymore because of trolling. im not sure about the other guy, though.

Yeah that's what I thought too, but then this guy started asking me some questions and I couldn't respond so I thought maybe it's some bug on chrome and I tryed playing on firefox but still wasn't able to chat... so I'd really like to know what's happening with chat :/