Visited Barcelona in 2015, at that time anti-tourist graffities were abundant at Gothic Quarter and generally visible everywhere in the city.
I saw some anti-tourist gaffities at Ghent as well, for example.
However, amount of them in Barcelona left me thinking.
Those are there because of overtourism, and the locals have a point. Europe is big enough, but if you have any sense you'll ignore Venice, Barcelona, Bruges, Amsterdam, Ghent, and even parts of Paris and Rome, and go to somewhere where tourists aren't mostly seen as a nuisance crowding out the local residents.
That's a whole other topic. There's a relevant part of Barcelona's society who reject tourists in general (not Americans specifically) because of the impact tourism has had in the city. Note that many still haven't recovered of the impact of 2008 GFC, 2010-2012 slump, with incomes still under pre-2008, and who are now having serious trouble to even afford a roof. So even though there might be some minor hostility towards tourism, it has nothing to do with americans. It's a problem in every major european city I believe.
