> 1) You want to buy something illegal from me, I send you a play store link to an app that costs $800 and is a picture of a cat. You buy the app, I send you th

> 1) You want to buy something illegal from me, I send you a play store link to an app that costs $800 and is a picture of a cat. You buy the app, I send you the illegal thing. If the feds find this out, and Alice and Bob and Carol also bought the app, don't you think that's probable cause? You're skipping the part where the feds have demonstrated that the seller of an $800 cat picture is distributing illegal goods. That piece of evidence is the probably cause for getting the list of cat picture purchasers. The cost of the cat picture itself, without evidence of a crime, is not probably cause. In this case, ICE does not have evidence of anyone committing a crime, or at least if they do they're not sharing it. > 2) Someone eventually figures out that an app seemed to have one purpose, but is covertly child porn. You mean, if you get past the first 400 pipes in flappy bird, and hit the 401st pipe, it shows child porn? Certainly throw the app maker in jail. You mean, if you hit the 401st pipe and it brings up an interface to exchange child porn with other users? Certainly get a warrant for the data exchanged over that channel. You mean, the app is Firefox for Android and it allows you to browse to childporn.example.com? No, that does not give you probably cause to get a list of all users of that app. None of these possible interpretations of your comment (if I missed your actual meaning, please explain) apply to the app in question. The app does not appear to be in and of itself illegal, nor does it appear to facilitate criminal activity. > 3) An app is found to be a private communication mechanism for a terrorist cell. No. That's every email/chat app in the app market. Every single one of them.