It seems like there just needs to be case law about the qualifications of an image hash in order to be counted as probable cause for a warrant. Of course you could make an image hash be arbitrarily good or bad.

I am not at all opposed to any of this "get a damn warrant" pushback from judges.

I am also not at all opposed to Google searching it's cloud storage for this kind of content. There are a lot of things I would mind a cloud provider going on fishing expeditions to find potentially illegal activity, but this I am fine with.

I do strongly object to companies searching content for illegal activity on devices in my possession absent probable cause and a warrant (that they would have to get in a way other than searching my device). Likewise I object to the pervasive and mostly invisible delivery to the cloud of nearly everything I do on devices I possess.

In other words, I want custody of my stuff and for the physical possession of my stuff to be protected by the 4th amendment and not subject to corporate search either. Things that I willingly give to cloud providers that they have custody of I am fine with the cloud provider doing limited searches and the necessary reporting to authorities. The line is who actually has the bits present on a thing they hold.