members random threads

have you ever had a member who posted completely random threads all the time...

there is the sort of thread that could promote a discussion, but it is way too short. like the one that was

title of thread: who has read?
first post: *name of a book*

or ones that the question is in the title of the thread, and the post is just a smiley or a question mark. that just really annoys me.

ive also seen some pretty weird and pointless polls, like "_____ or _______ which one do you like the best" and the possible answers are yes and no :doh:

what do you do with members who do this all the time?