I was wondering quote often about data possesion. It is their software. It sits on their servers. They convert and maintain it. Do i own my data? Currently - of

I was wondering quote often about data possesion. It is their software. It sits on their servers. They convert and maintain it. Do i own my data? Currently - of course I do not. They do with it whatever they want. They sell it to whom they want. I have option only to not use their service.