social.growyourown.services is one of the many independent Mastodon servers you can use to participate in the fediverse.
Single-user Mastodon instance for the Grow Your Own Services site

Server stats:

5
active users

Fedi.Tips

@faduda

You're not identifiable under a Fediverse username unless you choose to make it identifiable. It could be a totally random set of characters.

I don't know what the legal definition under GDPR would be though as I am not a lawyer.