This applies more to the ladies on the streets rather than to "our" ladies, but perhaps a slightly different technology can help out here?

The shoes look more "colorful" than discreet, but maybe that is the purpose.

every street walker would be off the street with those things... not for being arrested,

Because they'd kill themselves wearing them...

I know technology is moving forward when the talented inventors of the world are designing shoes with satelite uplinks, TV monitors and alarm systems all fashionably combined in a suitcase sized elevator sole.
My question is what are they doing to help with those tired feet? It can't be that much more difficult to install a foot massager in there.

"shoes for defense"

Thoes shoes make me want to go dancing, and do the hustle!!

Yeah, I can see how this would work...

1. Criminal attacks prostitute.
2. Prostitute says "Wait a second! Give me a second....." (grunt)...."While I....DOH....fold...myself in - GRRR - HALF....so I can push this stupid.....THERE! GOT IT!....panic button all the way down here at the bottom of my 6 foot elevator shoes"

3. Prositute stands up, takes a deep breath after her aerobic contortions. "There! Hey, thanks for waiting. Ok then, where were we? You were just saying you were going to rob and rape me, right?"

Yes, guaranteed to work. You betcha. And the shoes are cute too. (not)

Better not have any clients with shoe or foot fetich - fingers might set off the alarm! Or what happens when the lady is walking a bit wobbly over to the bed and knocks up against something - woo-woo

Don't get me started here because I know every single bit by heart and there're not enough one's and zero's in the universe to keep me going all the way.