Depends on the context. Are you copying someone else’s identity in order to make a passable clone? Are you trying to sell that clone?
A duplication of someone’s voice, commercialized by an unauthorized source, is definitely a form of stealing.
Copying information illegally, such as private information held on a private device, is overwhelmingly illegal.
In general, copying information is only as legal as the purpose behind it.
This is like Satan saying “We’re not going to be able to deal with mass corruption. Just burn everything. That’s the solution.”
That’s an interesting idea… Satan…