Not true, you can have privacy and at the same time not tolerate child pornography, those are two perfectly compatible positions and arguably the current state. What you can not have - by definition - is privacy on the one hand and on the other hand no privacy in order to look for child pornography. You can still fight child pornography in any other way, but when it comes to privacy, you have to make a choice - give people their privacy or look through their stuff for illegal content, you can not have both. If you have enough evidence, a judge might even grant law enforcement the permission for privacy violating measures, it should just not be the default position that your privacy gets violated.