It seems like a preventative strategy is to link my HHonors account to Amazon even if I never want to use points there. At least if I've linked it, someone else can't link it. If anyone tries this, be sure to uncheck a box which says to pay with points automatically.
Edited to add: After linking Hilton sent me a direct email, "Your Hilton Honors Account is now linked to Amazon.com."
Last edited by rrgg; Apr 19, 2019 at 7:06 am