@Steve K.
Why I think it's a new agent? I know many people that would laugh at such a request. Let's assume that's half of the people in a market. The realtor now can only work with half of their potential customers. Beyond that, who is going to refer someone that operates like that? In our reia, we probably would laugh about this person a few times a year. Just saying. I'm sure if this is a hard and fast rule, demanding an ID in order to work with someone to make a nice commission - they probably have a bunch of other exclusively self serving demands of their customer. To me, it would seem difficult to sustain yourself in a sales position with this approach. I've probably worked with 12-15 realtors over the years. No one has ever asked for ID, and it would be memorable if one did.
It's not them seeing the ID, it's also them being a responsible custodian of the information. When large companies, like Home Depot get hacked (40,000,000 customers) and they offer 12 months of credit monitoring, as their way of making things "right" - that's not enough to offset a lifetime of a compromised identity and all of the headaches the come with it. Their settlement, from what Google tells me, amounted to less than 50 cents a person.
Do I think a realtor is going to protect my personal information in the way it should be.... uh... no. Some certainly would, but probably not even the majority of them would.
As far as a safety issue - pack heat and be trained and proficient in using it. I realize that's not a perfect solution, but certainly a better one. I went into a business a few years ago, and on the outside door, it said "This is NOT a gun free zone." I don't think anyone will try any funny business there.