Why are there mean people online these days ? [I Love Internet]

I noticed there are a lot of mean and stupid people on the internet these days no offense to anyone but there's not just mean people on Yahoo Answers but there's some on here too. Some who answer questions just like to and make a big joke of an answer especially those stupid Anonymous trolls on YA who call users Sherlock and Sapina the crying trolls no matter how many times they get reported they wont stop and the sites don't do a damn thing about them. They just think asking questions on the internet is a big joke and don't take things seriously. Yahoo use to be nice before the teenagers found it. I was on there for 9 years I had to get off because of all the mean trolls I been using this and Reddit. I haven't been on Yahoo since July. Why are there so many mean people online now ?