This is a key reason behind my discomfort with social media. The algorithms that seem unresponsive to clear signals of intent was the last straw. Ended up leaving YouTube over the incessant push to new channels and ragebait shit.
Anyway, lemmy might be a cesspit at times, but its a cesspit I can choose/not choose, to engage with, and thats some nice anti-monopolisation of my online experience in the design.
Regarding how quickly Instagram started sending them personal stuff… Letting an app access your location, especially if it’s not a one-time authorisation, is basically telling it who you are.
There was a newspaper investigation recently on data brokers, they approached one to get a sample of their data. It was “anonymous” data, only in the sense it didn’t contain names. Using Apple’s advertiser ID, they had no problem building profiles from specific devices and could easily identify a lot of their own employees, simply because their routine around a location made it clear it was their workplace. And from there, it was not hard to find out on the data what their home address was.
It probably took only location for the burner phone Instagram to know that this is either the same person, or someone closely related to them.