The internet is full of data you can use. Just crawl it, like everyone does. There are thousands of open datasets, some gigantic in size. If you have sensors (camera, GPS, orientation, etc) you can generate a shitload of data. If you can create a game that is related to the data you want to collect, then you can collect data for 'free'.
On the other hand, think about it: what do Google and FB have that we don't? Personal data. What they have is data that is useful to target ads. If your interest in AI goes beyond ads, then you don't need that data.
On the other hand, think about it: what do Google and FB have that we don't? Personal data. What they have is data that is useful to target ads. If your interest in AI goes beyond ads, then you don't need that data.