These cops sound like a serious problem, but IMO it depends what you value: privacy or catching every cop who's like this.

If you want true and extensive privacy laws, we won't catch a lot of people doing shit like this. That's the world we live in and you'll have to accept that there are consequences for serious privacy laws. The more privacy you protect, the harder certain investigations become and the less law enforcement will be able to do in a certain amount of time.

If you want to be able to catch people like this, you have to have specific allowances for people's texts to be stored, downloaded, read. It infers that someone has methods to do stuff like that, and that can be used for good and evil. This becomes harder and harder to do well as you allow it more and more. The less people who have access, the less that will be found, the less that can be done. The more people and the more breathing room, the more likely you are to have serious issues like people a cop reading their ex-girlfriend's texts and using it to harass her.

I'm not trying to pretend it's a black and white issue - it's certainly not. We're not in a state where we're on one side or the other, and it ranges to different extents, and becomes more complicated with different types of privacy invasions, different methods and mass surveillance. I only want to say that there are consequences no matter which way you go. A lot of good can be done if you let LE search people's texts and emails in the event of an investigation. A lot of bad can be done as well.

I personally value privacy a lot more and believe that we should just accept the fact that there are a lot of people who will get away with a lot more and LE won't be terribly effective in those respects in investigations. But I accept that is an extreme view point.