A fringe website featured the purported names and addresses of the Fulton County grand jury that indicted Trump and 18 others for their efforts to overturn the 2020 election.
Give me your name and the state you live in and I could probably find your address, phone number, age, the name of your spouse, siblings and other family members, maiden name (if applicable), previous addresses, and even arrests, with about 10-30 minutes of googling and using only the top 1-3 results. Unless your name is John Smith or something very common, then it would be much more difficult. So, yes, it is public information and nobody has to have had to leak it.
As a Smith with a common first name, it usually sucks but I'm happy when it sometimes causes me to have some anonymity. If gone to pay my tab before and given my last name and there's multiple Smiths, which is fairly common. Then I give my first name and there's still more than one. It's somewhat annoying in that case, but good luck looking me up online.