Casinos vs Counters
It is a myth that card counting is illegal in US and in the other countries. When card counting is done without any help of outside devices, it is totally legal.
There are no laws which prohibit a blackjack card counter to make use of this technique in blackjack. However, since it gives the player an edge over the house it is not popular with the casinos, but used to in blackjack games online. Because of this casinos have been barring players for years that use card counting for winning the game. In Las Vegas especially, since the casinos are in private properties they are allowed to decide which blackjack card counter they would allow to play.
Ken Uston, one of the earliest card counters had won a high profile case against casinos in the Atlantic City when the court stated that casinos cannot ban card counting players. Since then several other measures have been used by casinos to discourage card counters.
Casinos use several measures to discourage card counting players like harassing the players by the staff by breaking their concentration. They also decrease the penetration which is the percentage of the cards that the dealer deals before shuffling the deck.
Other than this the casinos use high tech gadgets for face recognition and keep a large book of profiles of the players who play regularly at the casino for identifying card counting players. Various scanners have been placed at the casinos by many casinos which are equipped in identifying card counting.
Surveillance rooms have been set up with computers in casinos which allow the staff to detect card counters. Whenever a player increases the bet amount, the dealer would shuffle the deck which makes it difficult to count cards.
Several casinos have also introduced new rules on playing multiple hands, doubling and splitting in the game. Many casinos also place a rule for flat betting so that during the game they cannot increase or decrease the amount of their bet.
Depending on the location of the casino, the restrictions placed by the casinos would differ. In Nevada there are no legal restrictions for the casinos for using such methods against the players. However, the jurisdiction in New Jersey limits the amount of measures that the casinos can legally take against card counting players.
In the past years, casinos also made use of harsh physical assault and other methods to bar card counters. However, things have changed in the recent years and casinos do not take such measures any more for fear of legal actions.