This is an interesting problem. On one hand, FBI probably knows that by figuring out the viewers for a specific time they can perhaps catch someone relating to

This is an interesting problem. On one hand, FBI probably knows that by figuring out the viewers for a specific time they can perhaps catch someone relating to child pornography. On the other hand, if it's allowed it can be abused in the future. It cases like this that I wonder if one-offs should be allowed instead of creating precedent. It's pretty much what happened with charging underage children as adults. Created a precedent and now 10 years olds can get tried as adults. (obviously not a lawyer)