I was in La pineda last year and i noticed groups of young south american men looking suspicious. I duno if its me or do you have gangs operating in that area?
Dont worry there are alot of south americans working in salou / la pineda mainly from the dominican republic lovely friendly people they tend to meet in the street in groups for a chat but not dangerous its just the way they socialize
South Americans have not been much of a problem in the past, but things change very quickly. However, I can assure you that you are in no more danger here than you would be in any other European town / city. Just be sensible.