The problem is they don't have the authority at all. They can't be going through your personal, private conversations etc without a warrant because of the fourth amendment.
On the surface, no they don't, but the fact remains that the current administration led by Trump seems to show no regard for the amendment.
Instead, like what happened with Biddkannavar, the administration is looking for any reason to detain someone, including "random search" which was the only thing that applied to Sidd when we was presented a list of reasons why US Customs felt the need to detain him. From what I can understand, US Customs had no warrant to detain him. Now this argument would falter if Sidd was a foreign national without citizenship status, but he wasn't. He's a US-born national citizen and therefore protected by the fourth amendment, but that didn't stop customs from using intimidation and seizing him until he gave the password to his phone.
This type of unreasonable search and seizure is against constitutional law, yet customs went ahead of it anyway. These actions would be grounds to impeach Trump, among many other things he has done, but so far it seems few in the GOP establishment seem willing to go through with it, though I have not checked for some time whether or not this is the case. The GOP and Trump's core voters don't seem willing to question him, however. Which tells me that under this administration and the GOP members who support it, the rule of Trump's law is considered superior to constitutional law. Any press criticism of him is met with accusations of falsehood. These are all telltale signs of a dictator or at least one in the making.
I'm saddened that the stay on the travel ban issued by the 9th Circuit was not pursued in the Supreme Court, as it would've been a good way to finally determine to what extent presidential executive orders have precedence over constitutional and judicial law.
Thus, if the people give up their resistance to him, these unlawful actions will continue unpunished. While things may seem hopeful now with the large amount of people protesting him, do not underestimate humanity's tendency for weariness, apathy, and complacency. Exhibit A: The Third Wave Experiment
And the state itself has proven time and again to suspend or cherry-pick constitutional law in times of crisis and war in the name of "public safety." Exhibit B: WW2 Japanese Internment Camps.
