Some developers have trouble being self-motivated. It can be tough for some developers to work when they haven't gotten up, had coffee, driven to work, and sat at a desk. I don't know why that would be, but I can confirm that work-at-home isn't for everyone.

And of course, some freelancers have been known to bill for more hours than they worked. There were some on our game that I know overcharged me. The right answer is to part company with anyone I don't trust, but that isn’t easy when they have code half-written and you need them. I have experimented with a site called Hubstaff.com to monitor freelance workers remotely. It grabs a screenshot every 10 minutes, allowing me to see what they were doing. Personally, I don't like having to monitor people like that, and they definitely don't like being monitored. It's a huge invasion of privacy, but if we were in an office and they were in a cubicle I'd be able to wander by and see their screens anytime I wanted. So... I guess it is ok.

Our globally distributed team did work well for this game, but if I were running a large game company again, I'd want everyone coming in to work each day.