It's become a pretty predictable pattern - when there's a problem, the TSA steps in and bans something in the hopes that it will stop it from happening in the future. It probably won't, but they'll do it anyways because they have to do something, that is something, so they have to do it. At this point though, I'm not sure what's left to ban. High blood pressure?
I saw these a while ago, but the links I found at the time all seemed to lead back to an Etsy page that no longer existed. I've now found another site where they can apparently be purchased, so if you're interested in these, check out Safadancer's Tindie page.
Pictures of cop cars with wheel locks (like this one) are not hard to find. Maybe we need more of that, because a cop who can't see that sign probably does belong in a handicapped space but not behind the wheel.