if you want read only access you can use the nick justinfan{randomnumber} and then join what ever channels you like. But its read only so you can't on even pull a list of a channels moderators without signing in with an auth. (The user list only shows active mods in smaller channels, but you can ask the server for a list of the mods in the channel if you have logged in with a valid oauth)

> $ ncat -C irc.chat.twitch.tv 6667

> NICK justinfan123

> :tmi.twitch.tv 001 justinfan123 :Welcome, GLHF!

> :tmi.twitch.tv 002 justinfan123 :Your host is tmi.twitch.tv

> :tmi.twitch.tv 003 justinfan123 :This server is rather new

> :tmi.twitch.tv 004 justinfan123 :-

> :tmi.twitch.tv 375 justinfan123 :-

> :tmi.twitch.tv 372 justinfan123 :You are in a maze of twisty passages, all alike.

> :tmi.twitch.tv 376 justinfan123 :>