Passwords Are Locks:
I agree with what you are saying, that it is good to change passwords, to change house locks, but if they break in, they may steal things from you. If they don't like what he is posting, then they may try to go into his account to edit his posts. If it was just about money, they could send his money to their accounts.
Ubuntu
I'm using Ubuntu Mate 16.04 and I agree with you, I prefer Linux related operating systems and have been using Ubuntu since 2007.
Upvote
I just don't understand how or why they would make him upvote them. Well, unless if they were to sign his account up for auto voting. Well, it is possible they got in and got his account to upvote their posts. If that is true, then these criminals are incompetent as thugs as it would be better for them to edit his posts. But I guess it is easier to upvote than it is to edit posts.
RE: Now they're even hacking my account to give upvotes FROM ME to people who support my main DOWNVOTER!!