For instance, the "sources" accessible through those keywords put in a google search query.
(Entertaining the question as if my claim was more controversial than any other in this thread, that is, as if Barcelona was not infamous as a crime ridden s hole where visitors are asked to practice war zone vigilance.)
Putting "crime capitals of Europe" into Google gets me multiple lists, only one of which includes Barcelona. The one which includes it places it 26th in Europe, behind a whole lot of cities I've felt totally safe in.
Feeling safe in the street is one thing, but those ranks miss that the big fat crime will try its best to be invisible and unnoticed.
January 2021: "Police in Spain have reported the seizure of 827000 ecstasy pills, 76 Kg of amphetamine, 39.5 kg of crystal methamphetamine, 89 kg of cannabis, and 1.65 kg of cocaine in what they claim to be the biggest drug haul in Europe"
In this sense, yes, has well earned sadly a place among European crime capitals. Indirect analysis as looking for sewage water biomarkers, place Barcelona among the European cities with a biggest abuse of cocaine, slightly bigger than London. This means that 5 millions of citizens in Barcelona consume more cocaine that 9 millions in London, so they almost double the average dose per capita. Antwerp (half a million) is a disaster doubling the London/Barcelona values in a weekend. They could go to Barcelona to detox. Those are recent values taken from here:
Being "safe on the streets" is what this discussion was about. Drug use is irrelevant to what was being discussed, with user "ResearchCode" claiming that Barcelona is a place where people "are asked to practice war zone vigilance", something they've failed to back up with any kind of sources.
With respect to the drug use, I don't buy that measuring use is a valid proxy for measuring abuse or "disasters" - assuming all use is abuse is a severely puritan value judgement. I'd much rather be around an ecstasy or cannabis user than an alcohol user for example.
Again, if there are sources to suggest that the streets of Barcelona justifies calling it one of the "crime capitals of Europe", feel free to supply them rather than presenting unsupported hypotheses about how drug users behave there.
(Entertaining the question as if my claim was more controversial than any other in this thread, that is, as if Barcelona was not infamous as a crime ridden s hole where visitors are asked to practice war zone vigilance.)