Three codes were hidden in the HTML source of the TRANSPARENCY post on the Investigate Ingress blog.

[1] 7l5nkse9osmf3i3e

[2] 2nteauq57atnqb25

[3] 1700145910555891725

Code #1

Observations

16 characters with the right amount of numbers for a valid passcode. This one will make you smile !!

Code #2

Observations

Again, 16 characters with the right amount of numbers for a valid passcode

Code #3

Observations

Try to split things up to get the passcode format these are not all numbers