Nostr data is public by design. There's no expectation of privacy or anti-scraping.
Discussion
No, but you can AUTH relays or put them on a server that is little-known or difficult to access.
But my larger point was about relays being "free to use" meaning that you have no say in things like retention policies, moderation, content, or throttling.
And they tend to only be "free", so long as they can keep the running costs down (because they have little traffic) or OpenSats/VCs pay.
For the record, I have two "free relays" that I let lots of other people read and write from, but if they turn into a hot mess, I'm AUTHing them both.