I recently set up an FTP site on IIS and allowed anonymous logins. Well, some Bozo left a bunch of folders (850 to be exact) that Windows won't allow me to delete ("Cannot delete file: Cannot read from source or disk"). One of the folders spells out "con.Tagged by D Syndicate" (using different characters) and many are named "{}{}{}{}{}{}{}".

So here are my questions:

1) What is this?
2) How can I get rid of all of these folders?
3) How can I prevent this from happening again? (Is it enough just to assign user names and passwords?)
4) Is there any damage to my O/S or files outside the FTP root?

JC