Three codes were hidden in the HTML source of the SEEKING MISTY post on the Investigate Ingress blog.
[1] 2if2vbpeo7wnced4rt2u
[2] wkbigouhguonesdlrowhriginde
[3] 5zvl26belamp69caow
Code #1
Observations
20 characters with the right amount of numbers for a valid passcode
Code #2
Observations
Kind of a bizarre one but try to split into the passcode format.
Code #3
Observations
18 characters with the right amount of numbers for a valid passcode