User pages may contain any text, images or code as long as they abide by the policies for those things. If the user in question adds something to their user page which violates these rules, their user page will be removed and they will be banned (see the blocking policy).
Inactive User Pages
If a user has not been active in over a year, their userpage will be removed. When the user returns to the Wiki they may restore their user page by reverting this edit.