My iPhone or some app must be listening to my conversations and pulling out the subject of the conversation and putting that subject in ads on my web pages etc I'm reading. I have had this happen a few times in the last few weeks. I'll have a conversation with someone, they mention something which I know I have never searched for and the next time I go to a site that has ads, there is the subject of the conversation. The last example is apple cider vinegar. How is this happening, is it legal, please explain?!
I can virtually guarantee Siri and your iPhone is not doing this. Apple would never allow it.<p>It might be possible that advertising plugins on your web pages is using the microphone, but you need to have authorized this on the iPhone. If you didn't I'm inclined to guess it's just pure happenstance that similar ads appeared near to your conversations.<p>But if I'm wrong, this would be easy to test. What are the web sites you've noticed this on? We could both go to that site and start saying specific phrases to see if we start getting ads that match them.
Isn't there an abundance of evidence that __any__ Facebook app is constantly recording you? I recall seeing that Facebook and the Facebook Messenger were...
siri is probably always listening for "hey siri" but probably collects keywords for directed ads, try searching the settings for options to disable it or read the terms and conditions to find out "who" (what) is listening to you