The Big Screen Litter-Bugs

I love going to the movies.  There is something so exciting about being in a large room with a ton of people watching a film on a huge screen.  We like to be entertained together.  I have recently been to a lot of movies and I can't help but wonder about something each time I go.

At what point did it become okay to leave your trash for someone else to clean up?

We are taught as kids to clean up after ourselves.  It is against the law to throw trash on the road and highly frowned upon to throw it on the ground anywhere.  So why is it okay in a movie theater?  The employees of the theater even make it easy by standing with bags as people walk out and the trash bins are always available.  I have never worked at a theater or even been in a custodial-like job but watching people pick up after grown adults just seems so wrong.  No wonder a box of $.25 popcorn costs $5.  The theater has to pay someone to pick it up and throw it away.

This just seems like a no-brainer.