Git security: enabe fsckobjects in ~/.gitconfig:

In order to prevent possible tampering with code in git repositories you work with (e.g. malicious manipulation of objects during clone, fetch, push…), check if these lines exist in your ~/.gitconfig and add them, if they don’t:

[transfer]
fsckobjects = true
[fetch]
fsckobjects = true
[receive]
fsckObjects = true

These enable git checking transferred objects for their integrity using their computed hashes.

Original idea from here: https://groups.google.com/forum/#!topic/binary-transparency/f-BI4o8HZW0
(and the corresponding bug on Debian here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=813157)