I had a Raspberry Pi 3 Model B lying around, so I turned it into a TOR node. Because why not? It's dead simple. And TOR is a really important project for the continued ability for journalists to work unencumbered, for dissidents to reach out past their repressive governments, and so on. So, contributing is, I believe, important.
I added raspiinfo to the fb1 output Adafruit 2.8" PiTFT as well for easy monitoring. It's fun to see traffic flowing in and out. After the grace-period of 3 days, it was shoveling about 60GB of traffic/day. This is expected to increase to at least 200GB/day after about 20 days of operation.
I'm lucky enough to have a 1 Gbit/s fiber connection, so there's plenty of bandwidth to go around.
My next project will be to run this tor node in a cluster instead. I have a feeling the lone CPU - with a mere 1GB of RAM for support - is going to get toasty very soon. Not sure how to do this though, but I'll tinker until I figure it out.
Update 2021-01-19: I never got 'round to building that cluster. It has, however, been running flawlessly for over a year now, shoveling traffic like there was no tomorrow. No faults at all, which is surprising to me because the SD card in my Grafana/InfluxDB/Telegraf RPi server died in less than 2 months, shoveling a lot less traffic. Oh well.