It needs some tweaks. Most notably, the ESI outgoing dialing string continues even after 11 digits have been dialed and it dutifully reports it. So, first is the access security, or some kind of parsing in the finished output to substitute *'s for the extra digits and hide the raw data.
He's working on the config file, notification, and window dressing, but I think it might be offered for a reasonable fee, making the entire solution in the $100 range with Pi. It requires a Putty Agent key, Tor, and Putty to work and runs on a 3B. We're working on capacities with a 16 or 32 G memory stick. At 78 bytes per record and 36 or so bytes overhead per file, it's a lot of storage.
