Three were hidden in the REINVENTION post on the Investigate Ingress blog.

[1] 3v2chomvoco4n4c4

[2] s9phy7b6ai9spepn7p

[3] 97kgt47ybrcg974

Code #1

Observations

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

Code #2

Observations

18 characters with the right amount of numbers for a valid passcode

Code #3

Observations

15 characters th3r3 are some 3xtra numbers