Nostr relays are likely better because their only job is to store and forward information. They have no concept of private vs public information and are untrusted by default. 

It's up to the client, rather than the relays, to keep private information encrypted and secure. 

A seizure of a nostr relay would be useless in this same situation.  

 It does not really matter wether nodes have a concept of private or public. The moment a node stores information and the moment that nodes have owners, they might be held responsible just like the Fediverse guys. Sad but true.