Disrespectful college students?

Why even bother going to cl if you aren't even going to take notes? I've had a cl where a quarter of the kids never showed up, those who did show up either did crossword puzzles, suduko, their homework or else talk to their friend who happens to be taking the same cl. Some bring laptops and go on Facebook or MSN. I just don't get. I find it extremely rude! And it is hard to try and ignore it when you can hear them talking or if they are sitting right in front of you. This happens not only in big lectures but small ones too. I know that there is nothing that can be done about it. I just expect more from college students. I mean, we are considered adults, act like one! Show some respect! Does anyone else get annoyed with people who do this? If you do this too, why do you do it? Yes, lectures can be boring, but have you ever thought about how it would feel like if you were the one giving a lecture on a topic and people don't pay attention to you and they do it openly too.