Should you be a paranoid tourist?

I know I am running the risk of receiving death threats from a certain ethnic group, but the NY Times said it first. Their article describes how unsuspecting tourists will at times pay a higher price or receive lower quality services/meals in Rome.

I would say one must be vigilant, but not to the point of being paranoid. I don't like it a bit, but I understand the (rather primitive and selfish) thinking of the locals - who would claim tourists deserve it. After all, we are invading their territory. Just be aware that this is going on, and you will be fine.