i was online by myself one time, and a lot of people started coming on to the server. these people werent whitelisted and died a lot to zombies. this was when the whitelist settings were messed up and the people that came on probably had taken things from various people, especially at spawn, as i recall seeing a zombie that day holding a diamond.
During the races I was repairing our shop and then went and looked around at everyones buildings. Being new to minecraft, I was curious about the design of the houses. I did not open and chests while I was there. I also know for a fact that there was more players than just me at spawn at that time.