On: Anyone can access deleted and private repository d...

[kemitche]

You can't reach out to any machines that have pulled down that commit and forcibly delete it, either.

[hughesjj → kemitche]

But you can prevent anyone from doing so in the future and cross your fingers that no one has done so yet

[b800h → hughesjj]

As per this post, if a lot of people have forked your repo in the past, then you're stuffed.