host address
some irc webclients will mask their users actual (IP or location address)
some dont
if you register your name under NickServ you can ask for a cloak from the networks staff
but for general use and purpose, the majority are pretty much left wide open
example, I enter your chat as Andaro
you can /whois Andaro
and see my IP Address >.<
Now naturally i wouldnt be personally worried, because im personally tech savy
but you can see the problems that would arise from that