Random Number Generators are never really 'random'. There are some algorithms that are very good but you can never know what they use.
Apart from that, casino's are there to make money. The odds and games are mathematically designed so that on average the casino wins. (also with real casino's) That's how they make a living. The money you put in is used to pay the wages of the staff, the building etc. and the pay out for the lucky winners. The interesting thing is...you could be a lucky winner
p.s. I'm not saying that casino's are cheating, but say there was a certain type of card game that has the odds in favour of the player...you would probably not find that in a casino, they'd prefer a game which has the odds (on average, say over 1000 played games) in favour of the casino. It's just statistics.