A fairly reliable and simple test is this: leave your phone around content for several hours of a different language and see if ads related to that language show up.
It's surprising to me that people here are still debating this. I believe it's been going on since the original iPhone came out after a friend told me a very specific product appeared for her on Facebook immediately after she spoke about it and went to go look it up on her phone.
I don't think Facebook would stop at any measure to get all the data they can from you if they can get away with it and frankly anyone who does is extremely naive. It's right there available to them. There has never been and may never again be a time when companies (particularly Facebook and Google) to obtain as much sensitive data as is available to them from us without our knowledge, without external oversight, and without repercussions due to the lack of legislation.
It's surprising to me that people here are still debating this. I believe it's been going on since the original iPhone came out after a friend told me a very specific product appeared for her on Facebook immediately after she spoke about it and went to go look it up on her phone.
I don't think Facebook would stop at any measure to get all the data they can from you if they can get away with it and frankly anyone who does is extremely naive. It's right there available to them. There has never been and may never again be a time when companies (particularly Facebook and Google) to obtain as much sensitive data as is available to them from us without our knowledge, without external oversight, and without repercussions due to the lack of legislation.