Safty
The Las Vegas Strip is one of the safest places in the country. I have routinely walked the Strip at 3 or 4 in the morning without so much as a panhandler approaching me. However, every city has it's criminal element and you should take steps to protect yourself from it. In addition, due to attraction of the large volume of tourists, the thieves can just as easily have come in from out of town on a "business trip", staying at a hotel, as local residents. This doesn't mean you should be afraid or limit your activities. Just follow the same simple common-sense steps you'd use when visiting any large city. 
A large crowd of tourists, money in their pockets, jammed together focused on the Bellagio Fountain Show or one of the other attractions, is enough to make a pick-pocket drool. ALWAYS be mindful of your purse or wallet. Keep your valuables well covered and don't drop your guard while checking out the attractions, gambling, shopping, at a buffet, at the pool, or even walking down the sidewalk. Shopping bags are nice but they're usually wide open at the top. You're better off with bags that you can fold the top over. 
Always use the additional dead-bolt lock when you're in your room. As fast as new key-cards and electronic locks are developed the thieves find a way to thwart them. Don't leave large amounts of cash or valuables in your room. The hotels will keep them in their safe as a free service. Moderate amounts of cash should be locked in your suitcase. The vast majority of maids and maintenance workers are honest, hard-working people trying to make a living. However, the only way the occasional "bad apple" can come to the hotel's attention is after guests have been victimized. 
When in a hotel/casino lobby or at the airport, always keep a hand on your luggage or set it in front of you. It only takes a second for a suitcase or bag to disappear. Thieves like busy places where people are rushing around. Hotel lobbies, casinos, and especially McCarran Airport, all fit this profile.