I usually have my camera's up most of the season - someimtes I'll pull them when it starts getting really cold - because they start eating up the batteries. Once I start hunting sometimes I'll move them around to different suspected 'hotspots' to see what's going on in those area's...

Luckily, I havn't had any problems with people messing with them. I don't put them on public land or anything though. They are all on my uncles land, so I think that helps keep out the riff raff.