-X- You have been added to #Channel by username1, level 100. If you do not want access to this channel, type /msg X remuser #Channel yourusername.
And if you think this could be annoying just turn on noadduser.. I know its not something important like the csc website working, but it will improve the quality of irc-life. Just a thought.
P.S.: I don't know if I should post this in Coder-com section too, as a suggestion.