ISP side traffic sniffing..
As someone who's worked for telco's & ISPs before, I can guarantee you that snooping happens quite often... and most of the time it's just staff, and they (most likely) won't do anything you'd care about with the information they glean. Quite often it's just part of network performance testing or general diagnostics and sometimes curiosity.. but very rarely snooping on specific individuals (we *know* you look at porn, download copyrighted files content, send compromising emails, we don't need to prove it to ourselves)
I remember getting access through password sniffing to a few pron sites in my day (after ensuring that the site was fixed-fee, so as not to charge the customer more) - no biggie. In a reasonably well publicised screwup in Oz, a large mobile firm made undelivered MMSs accessible through a simple URL hack (luckily no personal details available along with it). I've decided that half the male population of Australia sends pictures of their dicks around, and that there aren't enough attractive women sending naked photos (but still a substantial number ..... and news for you, girls, guys DO forward your photos to their friends.. oh, the duplicates that I saw!) .. other interesting hobbies inside the workplace included searches on the SMS database for various words.. people are funny, when they think nobody's watching. :-) Statistically speaking, nobody is, of course. :-)