system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] In Rise of Skywalker, how did the galaxy know Palpatine was actually alive rather than just an impersonator who hacked into the Holonet?

Did anything actually happen immediately after his announcement to provide evidence his return was real?
gpt
They didn't know he was actually alive.

This is why the Resistance needed information from a spy within the First Order to confirm that Palpatine had returned.

Also, it was not known to the public that Sheev Palpatine was a member of an obscure religion that was wiped out a millenium ago. This gives a great deal of legitimacy to those in the know like Leia and Lando.