Comment by wallywax

For a while (not sure if they're still doing it), they were checking IDs for multi-day ticket holders at Disneyland in California (no fingerprint readers there). It slowed the lines down massively. I've been to both parks many times, and the fingerprint readers are immensely faster than checking IDs. For annual passes, they scan the pass and your picture comes up on the screen, but that's not as practical for a 3-day ticket.