Doesn't have anything to do with 9-11-01. If you'll have a look at around, somewhere around there should be flyer posted, explaining the reasons and such: you can't make 1/1 color copies of anything money or equal to money (money, stock coupons and certificates, stamps, monthly bus tickets, etc), you can't make 1/1 color copies of any forms of gopherment issued ID, and, if you're attempting to make copies of a book or the like, you'll have to have a form signed by the author that he aggrees to your making copies of it. Ditto photos made by a pro photostudio (if you have Tom, Dick, Harry and Associates take pics of your wedding, THEY own the copyright!), or pretty much anything else.
Something to do with the Digital Millenium Copyright Act (DMCA), if I remember correctly.
Again, has nothing to do with 9-11-01.