Spam is everywhere. Try adding words like sponsored, iPod, afford, buylegal etc to your keyword filter (tools > options > filters > keywords). Depending what you're looking for, you could add .mov & any other extensions you don't want to see. wma/wmv files are probably good ones to filter out too, unless you're specifically looking for those file types
What you should know about wma files

You can find more advice about filtering out spam/junk in the threads below, or use the forum search to find more info!!!
Words to add to keyword filter
Junk Filter

Be aware that blocking IP addresses is fine as long as the spammer is using that particular IP. Then, a couple of days later, someone else may adopt that IP address & you end up blocking an innocent sharer.

Here's some info about CruX, Google is always handy for finding out this kind of info.
http://www.cruxp2p.com/