There is nothing in that thread that proves it could happen, let alone is happening, beyond "my friend says it's possible" and then everyone jumping on that as

There is nothing in that thread that proves it could happen, let alone is happening, beyond "my friend says it's possible" and then everyone jumping on that as if some random person assuming something is possible is the same as it's actually happening. A falsehood only needs to smell like the truth to be believed. Access to photos is definitely happening but the rest is conjecture without some proper research into this. Ultimately this seems like far too much hassle and processing for very little gain, given the 2 seconds of audio in a live photo is bound to be useless for determining product relevance. Advertising algorithms are clever enough to target well without having to go to the expense of analysing real time audio from your mic or your photos & videos.