Snooping is bad, but I think if your partner has given you a reason to be suspicious, then it's primarily their fault for not being open and honest. Of course if you snoop, and don't find anything, then it's primarily your fault for being insecure.
I had a boyfriend who was always suspicious of me, which he admitted his trust issues came from the fact that he'd cheated on several girlfriends in the past and knew how easy it was to hide something from someone, so I was always suspicious of him. So, once I did snoop, I found a lot that he had been hiding from me. If your boyfriend doesn't have a history of cheating, and hasn't given you any reason to be suspicious, then snooping would be bad. If that's the case, then you should really examine your own feelings, is this an insecurity? Is it paranoia? What have you experienced that might make you feel suspicious of someone who hasn't given you reason to doubt them.
