The government gives itself the power to detain information at the border, holding laptops and other other data carrier as long as they like. They can copy the information contained within, distribute it to other government agencies, and use it however they like.
The purpose of this is to protect us from terrorists, who would presumably be crafty enough to stash critical information somewhere besides the most obvious data carrier in the world. So, like gun control laws that disarm law-abiding citizens but not criminals, the government now declares itself powerful enough to control the flow of information to those people who don't make efforts to conceal it. In other words, the only people to be affected by this will be law abiding citizens.
You would think, at some point, that Republicans who fancy themselves in favor of small government would object to the current administration's massive expansion of government power. But Republicans are so afraid, they'll let the government do anything it wants as long as the government promises to protect them from a risk so minuscule it can barely be quantified.
They do this, ironically, in the name of freedom.