The automation one is so true! When I first deployed a huge job to MTurk, with so much money on the line I wanted to be careful, and I wrote some heuristics to auto-ban Turkers who worked their way through the HITs suspiciously quickly (2 standard deviations above the norm, iirc) - and damn did I wake up to a BUNCH of angry (but kind) emails. Turns out, there was a popular hotkey programming tool that Turk Masters made use of to work through the more prized HITs more efficiently, and on one of their forums someone shared a script for ours. I checked their work and it was quality, they were just hyper-optimizing. It was reassuring to see how much they cared about doing a good job.