Electronics360: "Malware Can Turn Computers into Eavesdropping Devices Without a Microphone"

Powered speakers (with a built-in amplifier) probably are not very good microphones; the reverse gain from the amplifier output to the input would be infinitesimal.

And yesterday I saw that Bose is being sued in a class action for selling the information from their app for headphones showing listening habits. I say strike back. When not wearing your headphones play some really disturbing techno music and just leave it running. Or play one song over and over all day when not listening to music. I think a nice Kenny Rogers song should get them to leave you alone.

If hackers think it's worth while to ease drop I say give them nothing to listen to.