About five years ago I exposed my electrum server publicly which I had running on my home server. I wanted to use it with mobile wallets from on the go and also liked the idea of offering the resource to other Bitcoiners globally. My home connection quickly got flooded with denial of service requests to that electrum server.
Five years later, on a different IP, different ISP, different hardware (same domain though), I still get up to ten requests per second (!) to that electrum port, even though I haven't advertised or ran an electrum server on that domain or IP for five years. This makes up about 75% of packets hitting my firewall.
Lesson: Don't advertise your electrum server, don't run an unadvertised #electrum server on the default port. Ideally use #Tailscale or something.
#selfhosting