how was this done? I see "0 changed files with 0 additions and 0 deletions." on all commits.. (just wondering)

See "man git-commit", it's in there. :)

you can modify git history by filter branch

No need to. See "man git-commit".

Pushed 4,027 commits to kanzure/streak Feb 20 - Feb 28

So longer than git has existed. Well done.

wtf, wizard?