All the tech giants collect data on you and track you.
Do you think Amazon has released the low cost Alexa Echo Dot out of the goodness of their hearts? They're collecting everything you ask it, figuring out what you like, and then using that to make you buy more. I doubt that it's listening all the time though - that would be a step too far.
Twitter, Snapchat and other social networks
All of these are ultimately advertising companies. They only work if your friends are on there, they can only attract people if they're free, but they are also an amazing way of collecting data about your interests. Perfect for advertisers.
This is the big one. The pioneer of targeted online advertising. I dont trust them at all, and they have been repeatedly found guilty of collecting data they were not supposed to be. "It was a bug". Or "We have stopped doing that". But it still keeps happening. Again and again.
Google is too pervasive for me to stop using them. And some of their paid services are very good. Plus they promise not to track you if you're paying. Do you believe them?
Everyone knows I'm an Apple fan so maybe I'm letting them off lightly. Apple collects as much information on you as everyone else. But they promise to keep it private (and use techniques to anonymise and encrypt that data).
The fundamental difference with Apple and the others listed above is that Apple has already made its money from you - you've paid for that iPhone or Mac, so they don't have the same incentive to use your data against you.
Spotify knows me in an incredibly deep way. Music is important to me and Spotify consistently gets it right.
However, I don't mind this data collection. One, I pay for a family account - their incentive is to look after me. Two, Spotify only knows about one aspect of my life. Three, Spotify is independent. If or when they get taken over I may have to revisit this.