If I can just butt in here and add my two cents - I think there are two good reasons for not snooping:
1. Snooping causes you to expend energy that would be best used GingAL - and you inevitably hurt yourself with what you find 2. You are often looking for information to make judgments about where your spouse is. You will never be able to come about this knowledge this way because you never know the level of honesty w/the OP, or with themself. It's disrespectful and will lead you in the wrong direction to judge intentions from observations, etc., and snooping is a more disrespectful way of doing this. It's an invasion of privacy in order to obtain information that is then used in a way that doesn't get you any closer to your goal.
That being said, the only real legitimate reasons to snoop are to make sure there's NO contact - what that contact is over is not the issue (you can't get in their heads and fix their thinking) - or making sure that marital assets are not being used to further the affair.
“No problem can be solved from the same level of consciousness that created it. ” – Albert Einstein