Probably because their contracts were all due at the same time. And yes she should have a contract. Does she ever hang out with her mate Aleesha now? I know she sometimes sends ass licking cards but don't know if they still hang out?
I don't think shes actually scrubbing thorough the CCTV to find something. I think she tells them to do something so they can upload the CCTV, look 'hilarious' and maybe go viral. In a few months time their contracts will be up and if they don't move out I'll guess that they don't mind any of Grace's shit.