Wouldn't a cloud provider hand out your data just as fast as an ISP, if someone comes with a court order? Or is it not so easy for the content industry's lawyers to get that data in the US?
I haven't seen this project before but a few reasons come to mind at first glance
1) Looks like it also runs a headless Transmission client, so you could use it as a seedbox
2) It can be tricky to configure VPNs correctly so that if the VPN connection goes down, your traffic doesn't spill over onto the clearnet. If this Docker image ensures that aspect works correctly then that's helpful.
3) It's a little complicated to setup a VPN connection on a personal computer just for BitTorrent use, without having other traffic (e.g. browsing) spill over onto the VPN. Setting this all up on a segregated remote box and connecting to the headless Transmission client mitigates that.
But couldn't ask the same question of the VPN that the grandparent post asked of the cloud provider? Namely, won't they turn your info over just as fast as an ISP?
