Eg. in your case, you would almost
certainly want to not leave "controller" running on your firewalls at
all times, but only start it up if you actually had a subpoena to
collect data, and then only with appropriate firewall rules to limit
access to it.
<> Not real security, but stop gap to buy us more time to build something
<> more proper.
Perhaps use certificate-based authentication to log in via SSH to remotely
start the controller ?