First and foremost,  you cannot cheat the house.  That's the biggest sin in a casino or cardroom.  If you do it,  you're better off getting caught in a Vegas casino these days than you were in years past,  because the old Draconian methods of punishing cheaters  (e.g.,  vise to the head or an icepick to the testicles) have become things of the past.  These days,  you're turned over to Metro Police right away.  Cheating will also get you banned for life in Nevada casinos.  In your local cardrooms,  especially ones in New York City where you don't know the exact owner,  you're taking your own life into your hands.  Try to cheat a bunch of Mafia types,  and you will most likely find yourself getting all ten fingers broken by a thug nicknamed  "The Ukrainian Hammer."

Cheating the house at poker is probably the hardest to do since you are playing against other people,  not against the house as in Roulette or Blackjack.  You'll see poker players cheating only rarely.

Fighting with other players is a quick way to get yourself kicked out.  If you throw a punch,  you're out.  That's pretty simple.  There was a fight at my table during my last trip to Las Vegas.  I was in the middle of a hand when one guy was jawing back and forth with another.  One fellow made a sexual remark to another player's wife,  who happened to be playing at the same table.  Next thing I know,  the two are rolling around on an adjacent table.  The guy who threw the first punch was escorted out by the police.

Cheating or stealing from other players is another way to get yourself kicked out:  You could reach over and take a chip or two from another player's stack or you could short the pot if the dealer or other players are not paying attention.  You may also be asked to leave if a dealer incorrectly pushes a pot your way and you refuse to give it back even though you know you did not win the pot.  But most of the cheating in poker rooms involves teams.  Colluding with a partner with the intent on cheating a different player will also get you both kicked out.

Failure to adhere to the rules of the casino or cardroom will get you thrown out,  like talking on your cellphone at the tables,  or throwing your cards at the dealer.  Most places post their rules on a wall somewhere.  For instance,  it always states that unruly or intoxicated players will be asked to leave.  But unless someone pukes on a table or begins urinating in the corner  (both true stories told to me by friends),  the majority of places will put up with almost every form of bad behavior. ...(more)

With the advent of poker on TV,  newer players are being silently brainwashed into thinking that the antics of Phil Hellmuth or other professionals are the norm. ESPN airs nightly highlights of on–the-field trash-talking from different sports.  The various poker shows like the "bad guys" because they get good television ratings.  Eventually,  delinquent behavior from the pros trickles down the ranks into casinos,  cardrooms,  and homegames.  It's a growing trend that will eventually get ugly.

Most people today have bad manners,  in general.  Add a heavy consumption of alcohol and the intoxicating rush of gambling,   and the dark side of a losing player often takes over and the person becomes a complete jerk at the table.  Being a jerk doesn't get you kicked out of a casino,  but it should.  I have been appalled by some of the verbal abuse spewed at other players and at dealers.  Unfortunately,  you can complain all you want to the manager.  They'll ask you to ignore them.  Meanwhile,  the jerk gets a slap on the wrist.  Cardrooms and casinos need to do a better job of policing table bullies,  and institute stricter rules on player etiquette.

My friend Otis recently covered a poker tournament in Europe and remarked how civilly the players acted towards each other,  even in the face of a vicious bad beat.  I thought that was remarkable because that would never happen in America.  And I was a little bit jealous of the professional atmosphere in European casinos.