In comparison with other western countries, violent crime is relatively uncommon in Spain. In fact, one of the attractions for expats is the sense of safety that many feel when walking around cities such as Barcelona. However petty street crime is rife in the city and precautions should be taken to make sure you don't fall victim to a mugging or bag snatch incident. Common sense behavior such as not carrying large amounts of money or ensuring bags are securely closed are as important here as any other city. Pickpockets work in groups, and are experts in diversion techniques. If someone tries to attract your attention or bumps into you, be especially aware as this could be a purse snatch in action. One particular scam is to throw a liquid similar to bird droppings on a person. This person is then approached by an apparently well-meaning passer-by offering to help to clean off the offending liquid, and then the victim discovers later that items are missing.