[andy_ppp]

What are the rules about datasets I upload to this free service? Do Google now own them?

[ColanR]

My guess it's the standard caveat: if you don't pay for the service, you and your stuff is the commodity.

[lern_too_spel]

I would imagine no more than it owns the files you upload to Google Drive. The disk on the Colab instance is ephemeral, so you will need external storage for your dataset anyway.