Absolutely!
But this isn't such a new phenomena. I recall decades ago, an old chum who had lived in NYC for a few years came back to visit in bucolic Roch-cha-cha. One night a group of mutual friends came over, rang the doorbell and came in. My friend asked me, "Does that happen often?" I asked back, what do you mean - people come over and drop in unannounced and it's okay? Friend said, "that never happens in the city. You don't do that. You call first."