If I had to put my account's life on it, those that say they was hacked was because they trusted the wrong person and gave out their log in information. They may not be case in 100% of the hacking incidents but given the gullibility of some in home and also innocence and naive nature of some users the hacking is self blamed. I could be totally wrong though.
Most people who threaten to hack do not have the ability to do so. They are just saying that to try to intimidate you. The people who are capable of hacking normally won't openly boast or threaten to do so, because as you said, it is a federal crime. But if someone does threaten, that's enough to make a report and let the mods sort it out.
Well if thats the case then you have nothing to worry about and if more new users had that same attitude then all hacking threats would never be thought of. I try my best when I see others giving out way to much information, to try and remind them that for one thing its against the ToS and not very bright and to be careful what info they give out. When I was younger I could never figure out how my parents found out when i was not such a "good boy"...years later my mom told me that 99% of the time I told on myself.
Remember too, no one from Sony will ask you for your information, there are people on home that say they are mods, but they are not, even if they are in a group saying they are in some kind of club" safty patrol" or "police"( you do not know how many I run into,lol). Also, some people are losing their accounts due to " greed".They see all the items one can get by" ISE" and some people say that if you give them your account info, they can give you stuff too. Be careful with whoever you deal with online, and, if you have family ( in rl) that share your machine, make sure they can't be tricked also.Or that they won't give your account away because they get mad with you. In the end, never fall for a threat, if some one threatens you, keep reporting them, and block them.
A few other security things to note:
Don't join random group chats on Home.
Don't give your date of birth out (security question for account recovery I believe)
Don't share your email associated with your account. Its also wise to have the email different from your ID as that can easily be guessed.
I would add don't go to a stranger private place to the random group chats. As they are way's people get get you're IP address. It happen to me when someone used a third person to invite me.
But I'm curious. What exactly can someone do with your IP address?