Can the owner of an open source Github repository later decide to close it? What about other people\'s contribution to that project?
Edit - several peop
Is it technically possible to take a public repository I own on github, and turn it private at a later date?
You cannot have private repositories unless you pay for them. Github's Plans and Pricing state that you can sign up for the free public repositories, and upgrade/downgrade your account at any time, so they almost certainly have a way to make your free public repositories private by upgrading to a paid account, or they would have a tremendously broken business model.
After reading their help files, you can indeed mark a public repository as private if you have a paid account.
You could also just delete the repository from your free account, and start hosting the repository yourself if you want to stop sharing it.