In order to claim a site as big as stars is rigged someone needs to show me some hard evidence (3 hands is not a hard evidence), if someone with a record of over 10 million hands or so will show something which is statistically inaccurate then it may be worth looking into it

From pokerstars support:
PokerStars shuffle verified by Cigital and BMM International
PokerStars submitted extensive information about the PokerStars random number generator (RNG) to two independent organizations. We asked these two trusted resources to perform an in-depth analysis of the randomness of the output of the RNG, and its implementation in the shuffling of the cards on PokerStars.

Both independent companies were given full access to the source code and confirmed the randomness and security of our shuffle. Visit Online Poker Random Number Generator for more details.

You can ofcourse claim those 2 organizations are in on the consipirasy, or that pokerstars submits one source code and runs another, but I doubt that.