Honestly one of the worst parts is I hate how police/the government can/will abuse these abilities if given a chance, because sometimes those few cases where they could be used they could potentially be really useful.
I work in 911 dispatch, we don't always have a totally accurate location from a cell phone, people sometimes repeatedly hang up on us, put their phone down and walk away, refuse to answer when we call back, or are too hysterical to answer any questions. Being able to put their phone on speakerphone remotely, keep them from hanging up on us, turn on their camera, etc. so we can see/hear at least some of what's going on could be really useful sometimes to help make sure we're sending the right kind of help to the right place. Being able to turn on a phone camera to see where a barricaded subject is in a building or room, see what kinds of weapons he has, hear what he's saying, etc. could be really useful sometimes. Sometimes someone will butt dial us or their kid playing with their phone will call us a few dozen times in a row, and it would be kind of nice to be able to come over their phone speaker and just say "Hey, you keep calling 911, if you don't have an emergency can you please stop?"
But cops would rather use those capabilities to harass protesters and such.