Why do you protect your cards in Texas Hold Em?

Players protect their cards so that others can not take a glimpse of their cards while playing. It is pretty easy to look into someones cards while playing Poker, therefore players protect their hand.... A card guard is used to protect you cards from being accidentlly pulled into the muck by a dealer as your hole cards are your receipt protect them at all time because if they are accidentally mucked you can not continue in the hand therefore losing any wagers made! looking at another players cards is not only very poor etiquette but can result in time penalties or exclusion from the game