Should people wanting to teach self defence have to be licenced by the local authority first? At present it seems that anybody can offer self defence training regardless of their ability to teach it, and charge a fee for doing so. Is this really anything more than simply exploiting the insecurities of vulnerable people?

I can't really see this happening, how for example, will a local or state authority know who is good and who isn't?

You could also get really biased people doing this. If self defense works, most people know it when they see it. Self regulation works much better.

After all, don't doctors make money out of sick people?

Should there be....yes, can there be no!
There are so many approaches to self-defense now how would(whoever is judging the criteria)they know which was good, better or best-Hell we don't even know that.we have had governmental interference here in Arizona, a senator stopped a no holds bar UFC type event here. He didn't like the idea of no holds bar fighting in his state. Upon this, we were worried what was next-Karate tournaments, kickboxing events? It would be real difficult for a board to exist, I bet the board wouldn't even get along. Most probably police officers would be looked at and we know that their self-defense is questionable. Regulation is needed, people walk into supplies stores and buy Black Belts, not even being a martial artist. There was a push to have supplies stores not issue a Black Belt unless the Sensei ok'd it, but people come and go, and the Black Belt list was basically was discontinued, but it was a nice try. I am sanctioned by Sensei's that aren't in my state as well, so how does that get resolved? regulation is needed, so is unity, but I don't think we will live long enough to see it.

Okay, I maybe need to expand a little.

Should anyone wanting to teach self defence have to first satisfy their local authority that
A: Their training facilities are adequate
B: They are trained to an acceptable standard in first aid
C: They are part of a recognised MA organisation, have public liability insurance and hold valid rank to teach within that organisation
and
D: They aren't some kind of madman with a criminal record for violence, or a sex offender or something.

Thinking about it, I suppose regulated is a better word than licensed.

Once again, it should be, but I doubt it will be. Here if you teach in a school system, you have to be tested for drugs and figer printed, recreation departments offer the space, so many times they are just filling space. C........Many schools don't like the politics of an organization, and many instructors do so in a garage or at a school and they are not in any organization. You can make the argument you should have to be in a Organization, but there are phonies there too. I know of one started by a brown belt, for Masters, and gave rank too. So your organization would have to be sanctioned or something. I too tire of seeing 14-16 year old 2nd degree black belts training adults and not being able to converse on their level, it give us a bad name, but my big question, who would regulate what goes on? The boxing commission would be my only guess, and we know how ethical they are.