1. so in your mind a search warrant can never be obtained because as long as there is no conviction they are not guilty so their privacy is more important, and if they are convicted the evidence is not needed anyway. You might want to think that one over again.
In this case a judge found that there was enough suspicion of wrongdoing to order the warrant. I honestly do not see what your problem with that is.
2. I agree. But this is a criminal investigation, and a proper warrant is available.
3 and 4. We will see. Yahoo tried the same excuse in 2013 and failed. I'm getting the popcorn.