California is the latest state in the US to ban interviewers asking potential candidates questions around salary history. The aim is to ensure that candidates are paid for the job they are about to do, and not paid just a slight increase on what they are currently on. It’s designed to ensure equal pay for equal work and I am sure it won’t be long until something like this is implemented here too.
https://www.natlawreview.com/article/california-latest-state-to-adopt-no-ask-law