[panic]

What happens if the private key is compromised, and you have to switch to a new one? Does the identity of the machine then change too?

[a3_nm]

Yes, but with IP addresses your identity changes whenever your connection changes, which is much worse. When using fingerprints, instead, the machine identity stays the same (and conceivably you would just have to ping a decentralized repository of "fingerprints => IP" mappings).

[dogem]

And with this identity it is easier to track you.

[a3_nm]

Nothing prevents a machine from having multiple identities.

[p4bl0]

Or for an identity to "jump" from machine to machine at times.

[StavrosK]

Necessarily, I would imagine.