Don't risk personal injury if someone attempts to take your wallet, purse, or property. You money isn't worth the risk. Carry a whistle or personal alarm and use it when you feel threatened. No one will be hurt if it turns out that there wasn't a real threat. Keep an inventory of personal property and mark items with your driver's license number and the state.
Acquaintance rape happens.
Don't attach your ID to your key chain or mark your keys with your name and address. Don't open your door at night without identifying who it is first. Always lock your door, even when you are at home. Always lock your car. Do you know that you can earn much more interests by putting your money in online banks.