indeed pauln is correct when he says that the cracking of the dvd protection is illegal. at the beginning of a lot of current dvd's, during the threats made about piracy it is clearly stated that it is illegal to crack or bypass the copy protection. i believe it has something to do with the software copyright, as in you may use the contents however you like but not change it in any way. like the open/closed source laws. but the movie itself you are allowed to copy by law as long as it is for your personal use only, ie you keep one copy in your lounge and another in your bedroom or whatever.
this is just another example of hollywood greed as they dont want you to make copies for yourself. they would prefer you to go and buy yourself a 2nd copy if the 1st one gets destroyed or for any other reason.