It's not that black and white. Private and confidential data is allowed; however, customs and border patrol also have legal authority to inspect such private and confidential data when you cross the border. They do not have the right to inspect it, without warrant, elsewhere.

This is the same in the US, maybe even worse in the US. Customs can inspect your home if you live within 100 miles of any border...

https://www.citylab.com/equity/2018/05/who-lives-in-border-p...