I saw a net gun used to capture Arnold in The Running Man. It's obvious that getting out of that net would take up precious TIME. Depending what it's made of, even a good knife might take considerable time to get you free.
I've seen various such ideas in science fiction novels. One that interested me, was a "tangle gun." It fired a projectile like an egg, which you aimed at the fleeing suspect's feet. Upon impact, it burst, throwing out super sticky "tendrils." It would entangle the subjects feet just as effectively as a South American Gaucho using a Bolas. With today's technology in adhesives, aerosols, quick expanding/foaming synthetics, etc. I'd think it's a possibility. Naturally, one would carry a spray can of "release agent" that liquified the tendrils.
From time to time, I've even wondered if a tough "cargo net," suspended from hooks surrounding your door before retiring in the evening, would seriously impede a team of invaders who smashed the door with a ram.
Entanglement can be effective. And it's passive. You aren't doing the subject any harm. Sure you can beat the crap out of him after he's entangled, but you don't have to, and the net didn't harm him.
“The police of a State should never be stronger or better armed than the citizenry. An armed citizenry, willing to fight is the foundation of civil freedom.” Heinlein