I've been to Barcelona as well, the beer sellers are terrible human beings. They will hover around you like flies, then one of them will put a beer down next to you in the sand. When you refuse it, he'll pick up the beer and say "Look, it has sand all over it, it's ruined now. Pay me for it." They are of South Asian like myself, and I'm sure many Indian travelers make the mistake of talking to them when the best thing to do is completely ignore them.

The next night I was ambushed by four of them in the subway, they wanted to put their number in my phone and started getting really aggressive. I smacked the shit out of two of them before a bystander intervened. If I had handed my phone to them I'm pretty sure I wouldn't have gotten it back.