Yes, it is. If someone leaves their journal lying in a coffee shope, I won't read it. If my neighbor leaves their Wi-Fi open, I won't hack it. If someone is talking a few meters away, I won't use eavesdropping device to listen to them, and if someone sends an unencrypted communication, I won't read it just because I have the technical ability to do so.

May I am slightly mixing my definition of personal with private, but where is the respect for other people?

"It's not personal if you broadcast it unencrypted" is the same line of thought as "she was asking to get raped". Just my opinion.