how to control posts that don't word wrap

Hi I had this happen where a user posted and purposely ( i think) just typed the letter "X" about 40 on the subject and endless on the Body. I couldn't even scroll over to the right because it was long. Shouldn't it automatically wrap long lines like that?

What ended up happening was it screwed up the front page when it was posted. Everything was stretched to the right because the teaser subject and body was just long. Is there a setting that can control this from happening?

Thanks.