Are you sure that you meant to post in 'History'?
Anyway, while I'm sure that there must be a temptation for the operators of internet Bingo sites to cheat the system, I doubt that many actually will. That's simply because they wouldn't want to risk losing the big profits that they can make by 'sticking to the rules'. One bit of bad publicity could cost them far more than they could make by cheating.
The foregoing, of course, assumes that you're using sites run by trusted UK companies, such as Mecca. (They certainly wouldn't want to risk losing all of the people who turn up to their bingo halls through publicity about some 'dodgy' activity on their online site). If you play bingo on the site of an unknown company using a Chinese or Nigerian server you certainly shouldn't expect to win (or, if you do, to actually get your winnings)!