Fair nuff, but I can’t help but think that it could lead to their home addresses; if I was a security person, I would worry.
Don’t they use any type of private security at all? Can I walk up to Antonin Scalia’s house, ring the doorbell, and Nino will answer it in his boxers*, holding a cup of coffee?
*Sorry for the mental image this early. 
When I was living in Ottawa, I often saw Justice McIntyre of the Supreme Court of Canada walking to work, down Wellington Street in front of the Parliament Buildings. I don’t think anyone would notice, unless you happened to know who he was. Just looked like some old duffer out for a walk.
Out of curiosity, I just looked up Scalia on LexisNexis. Weirdly, there are two Virginia phone bills in that name in Virginia, but neither of them goes with an address that in his, his wife’s, or his children’s names. His voter registration has also apparently been redacted (or possibly he’s not registered to vote); I found two Antonino Scalias born in Jersey in 1936 but both are Democrats. 
And making a traditional Italian hand gesture with his other hand.
OK, so beefed-up security isn’t needed because the Supreme Court justices don’t, in practice, get many or any assassination attempts, but I’m still not clear why that should be so. KarlGauss does seem to have a point, that they’d be logical targets for political extremists of one stripe or another. Is it just that the kind of person extreme enough to attempt assassinations in the first place isn’t likely to be rational enough to choose appropriate targets?
Since the SC decides their own schedule and cases, if someone were to make an overtly political move such as killing one or more of the members before a case, couldn’t the SC just table their session until a new member was confirmed?
Somewhere around here is my copy of Secret Service Chief, the memoir or U.E. Baughman, who was head of the Service from 1948-61. I believe he mentions a Justice complaining that somebody was going through his garbage and authorized some agents to look into it.
He also mentions addressing some of the expressed concerns of Secretary of Defence James Forrestal, who said he was being followed. Baughman learned later that Forrestal was sliding into severe mental illness.
This is from memory - I’ll confirm if I find the book.
I’m pretty sure that the Justices to get some security personal. Here’s an article about Thomas asking for more money for “threat assesment” and security personal for the SCOTUS, and according to the US Marshal’s service in 2011 they:
They don’t seem to have the same 24-7 protection the Prez has, but they do seem to get some form of access to security personal even when they aren’t in the actual Court building.
I couldn’t find much more detail, presumably the Marshals don’t advertise the specifics of whatever security measures they may have.
If they have gaps in their security, then they could hire their own. IIRC, a justice makes a quarter of a million in salary alone. Not a vast sum, but enough to hire some private security. If not, I’d be for giving them a raise and letting them decide themselves if they want more security, or if they want to spend the extra money on hookers and blow.
-XT
Personnel. A security personal is presumably what you put in a newspaper when you want to hire a guard with benefits.