Question over new movie Bruno/Rant.?

Now i know this movie is rated R... and i'm 17 years old and at my theater you need a signature of someone 17 and over to get you into a rated R movie, and i was going to get my two friends in, but they were like no, you need a parent to sign you in and "Sit with you in the theater" if you're under 17.. and the person to get the tickets from doesn't even ask for IDs for some of the people. Now tell me what is the difference between signing a couple kids into a movie knowing what it's rated for and why( there was a sign saying graphic nudity of male private parts) and having to have the parent sit with you, if the parent knows your going to see this movie and what's in it, why do theyneed to be sitting with you// it makes no sense. It was definately a controversial day as the people at my theater are retarted at carrying out their job... I was just more upset that she lets people in without IDs because she umes "oh they're old enough" another typical person who judges people all the time, if you're going to have a Rated R movie, WHY NOT ask everyone for IDs.... sorry for this rant.