Did you know about this feature? Up until now I had never come across it!
Windows XP SP2, Windows Vista and Windows 2003 have this deal where zone information is preserved in downloaded files to NTFS partitions, such that it blocks certain files in certain applications until you “unblock” the files.
So for example if you download a zip file of source code to try something out, every file will display this in the security settings of the file properties
“This file came from another computer and might be blocked to help protect this computer”
Along with an “Unblock” button. Some programs don’t care, but Visual Studio will refuse to load projects in solutions until they’ve been unblocked.
While it’s not terribly difficult to go to every project file and unblock it individually, it’s a pain. And it does not appear you can unblock multiple selected files simultaneously.