Sounds like you just havn't found a decent job yet, I nearly lost my job 2 years ago due to internet / email abuse, proper cacked myself, was very lucky and got away with a written warning (2 other people got sacked due to the content of their emails).

If you find a job you want to stick with just check the company policy on internet & email use, my Company allow up to 6 personal emails per day and 1 hour personal internet useage during working hours..... it is damn hard to stick to it but not worth loosing my job over.