It is very probable that you heard some scary stories of stolen backpacks and wallets before you even came to Barcelona. And after arriving you have probably heard some more. Even if you are from here or have lived in the city for many years, you always know you should watch out for some classic problems.
Barcelona is not a seriously dangerous city in comparison to many others, but it has some features worth noticing in this sense. Pickpockets on Las Ramblas are the very obvious example of this. For a tourist and a permanent resident alike, it is useful to remember a few everyday things. These are a must if you want to avoid a few annoying (and possibly devastating) situations so typical in the lively capital of Catalonia.
The problem Barcelona is the most famous for is pickpocketing. You should keep in mind though that this is not just a touristic phenomenon happening in the center. Looking after your purse a little bit more than at home is therefore not enough. If you want to make sure you leave with the same bag you came with, you should not leave your belongings alone in any public place, and this includes most shops and other safe-seeming spaces. Avoiding thefts may seem self-evident but the level of pickpocketing in the city is so high that avoiding it often means a substantial change in habits for those not used to it.
The second problem some tourists face is cheating regarding taxi fees. Make sure you do not pay any supplements, unless you are sure it is needed due to for example luggage or point of pickup. In general, the taxis of Barcelona are reliable, though, so this is not a problem you need to stress about nearly as much as pickpocketing.
There is a third common touristic or expat problem, but it is luckily quite easily avoided: accommodation-related trouble. Most foreigners from very modern countries are not used to hot water running out in the flat of their dreams, and they do not expect freezing cold winter nights in expensive flats. Barcelona is an old city, and if you have an unmodernised flat, the result is less comfort. If you have a taste for modern comfort, it may be best to limit yourself to fully modernized accommodation – no matter how beautiful some bohemian Art Nouveau flats might be. And naturally, you should only rely on established and well-rated services. This way you can make sure your holiday flat or rental studio does not cause you any unwanted surprises.