Are there dangers associated with allowing files like PowerPoint files to be uploded using modules like NewBB2 or WF-Section?

I am about to embark on a site where users will be able to upload copies of PP files that they used for presentations and conferences. But obviously I wanted to minimise the risk of my web hosting space or the users of the site being affected by hackers planting trojans and stuff in the files. I also don't want the site being compromised (I'll be using Protector module which will help)

Some hosts run anti-virus. Would this prevent the dangers?

I wouldn't allow just anybody to do it.

This reminds me of one reason I love unix/linux sooo much. Although I'm sure it's happened, I just can't name any Linux viruses. I bet if I ran AVG Virus scanner on my Windows box right now that it'd find at least one.