You realize the current prison population has jack-shit to do with what we're discussing?
I know bad laws exist. I know they still have (terrible) effects on real people. I'm not an idiot. I know circumstantial evidence can get a person convicted (but not, hopefully, without more than one piece of it. In which case the defense fucked up their job, the jury fucked up their duty, and the prosecutors... well, good job, guys.). A legal case is always, to a certain degree, playing the odds with 12 people you never met and whether or not events have conspired to make you look worse (or better) than you deserve.
But I don't think bad laws existing is reason to say "we shouldn't do this other thing that does more harm than good."
I think bad laws existing indicates "We need to fix fucked up laws."
So, tell me, Truean - You have a client come in, who wears one of these, recording 24/7.
The police have accused him of a certain crime at a certain time in a certain place.
You have access to this recording that shows he wasn't even there.
Is this, in your mind, a bad thing? Is this... no helpful to you for some reason? Is this evidence in some way weaker than it appears?
You seem to be a victim, here and in other situations, of always being able to see what could go wrong, which I'm sure is useful in your line of work, but you seem to have difficulty in seeing what could go right. Do you honestly think there is no benefit a person could gain on a legal front (both as a defense, and in convicting those who committed a crime against them) to these items? Is it inconceivable that for at least some portion of the population, those benefits might be more likely than the negatives, and more valuable, and thus worth it?