Because there are so many corrupt files, some of which I've downloaded, I have my downloads go to a folder that isn't shared. When I get around to it, I check it out and, if it's ok, I then put it in my shared folder. If it's bad, I trash it and try to find another. At least I can try to do my part not to share bad files.
Now if we could just get people to quit sharing their Incomplete Folder/Files...