Beware of pickpockets as they tend to operate in tourist areas, keep your belongings secure at all times and be careful if strangers try to make conversation or distract you as it could be an attempt to steal your valuables.
Credit Card Fraud
Credit card fraud, cloning cards can be an issue be careful where you use your cards. Also if you are withdrawing money from cash machines make sure you cover your pin and be discreet about the amount of cash you withdraw.
Be cautious of men offering to help you carry luggage, particularly around Piazzale Roma. Although not dangerous, they may demand a large payment in return that you are not willing or were not expecting to pay.