Rowdy groups of bachelor parties. Backpackers asking locals to pay their way. The hordes that pour daily off cruise ships, choking up city centers.
It wasn't so long ago that tourists were (relatively) feted in the destinations they visited, with locals relishing the chance to earn money through a tourism economy.
But today, with traveler numbers becoming out of control, and tourists dwarfing local populations in popular cities from Amsterdam to Venice, things have changed.
Today, the challenge is to be a "good" tourist. And as we try to travel to places without making a negative impact, destinations are becoming emboldened to speak openly about which kinds of travelers are welcome -- and which are not.