Just letting this pdf here about security of Seedboxes: https://media.defcon.org/DEF%20CON%2031/DEF%20CON%2031%20presentations/Anon%20-%20Mass%20Owning%20of%20Seedboxes%20-%20A%20Live%20Hacking%20Exhibition.pdf
I could see the real source IPs for all other users in
last
logs.
Accessing their web interfaces shouldn't be a risk, as you've already paid them and thus left a paper trail. But the point about accessing the IPs from the last ssh (or sftp) logins might be worth using a VPN for. If another user is able to get them law enforcement could too (not that it's likely).