Bonus Fraud
Anyone who can "abuse" a bonus with 200x WR is clearly up to something
Casinos seem keen to muddy the distinction between bonus abuse and fraud, with the implication that those who win with their bonus must be committing fraud, but the casino is having trouble working out how (perhaps because the player didn't). They then bring out the "abuse" accusation to deny the cashout.
Unlike a court of law, it is usually down to the casino manager's "gut feeling" that cash-ins are denied and the player called a criminal (Fraud is a crime, whether committed by player or casino).
Business, be it casino or double glazing salespersons, find it easy to screw the customer, and some rogue characters deliberately set up shop to do this from the outset, given that casinos are less regulated than double glazing companies, it is hardly surpising that fraudsters are attracted to the idea of starting their own casino.
Casinos now suffer the consequences of this cavalier attitude in the development of the player fraudsters. They see casinos getting away with "murder" and just want a slice of the cake too. Casinos then have to tighten even further, and end up screwing innocent players, who then may decide that the whole industry is corrupt, and that they cannot get a fair deal unless they play the casinos at their own game. This began with "bonus abuse", and soon went on to multiple account bonus abuse, using false identities to have several goes at the bonuses. Beyond this, financial fraud, with fraudsters using money from stolen sources to play (or withdraw into a "clean" account); this includes players who make a chargeback when they lose and pocket the winnings when they win (there are a few casinos that do this also, deny a cash-out when a player wins, but happily accept deposits and play when the player is losing - if a player is in breach of terms, they are just as in breach when losing than when winning, so ALL wagering should be voided, not just the last winning session).
A definition? this has been discussed at length, but casino operators will not define what is a bonus abuser, as doing so would limit their ability to identify other forms of abuse. Initially, abusing a bonus meant making thousands of tiny bets on a game like Blackjack and cashing out at the end of meeting WR with a small profit. Now, abuse includes making a very high risk bet, or series of bets, in order to win big or die very quickly with the bonus. As soon as another strategy turns out a significant number of winners, this too will become "bonus abuse" - this implies that playing to win is sufficient to attract attention.
With casinos making bonuses ever more complicated, players need to get cleverer too, and many websites have sprung up to cater for this, and now a brand new form of bonus abuse emerges, playing by rote (usually the accusation is that the new player got a skilled friend to play for them, and they justify this by saying that their pattern of depositing for the maximum bonus and playing skillfully means that they MUST be a member of a ring of friends rather than playing for "their own entertainment".
(Another one bites the dust and gets uninstalled. I can see my desktop!) I guess I don't usually deposit much beyond what is required to receive the bonuses, so therefore I don't qualify to receive the bonuses anymore. 
You do this by playing their games.
