The EU has issued new regulatory restrictions mostly impacting American companies that could pose challenges for President-Elect Joe Biden. EU Competition Commissioner compares the proposals to the “first-ever traffic light that brought order in the streets,” but a Biden advisor says the taxation and the data privacy rules have the potential to be a “grenade.” The proposal out of Brussels is a triple whammy for U.S. tech companies: they will take legal responsibility for content, they must allow equal access to their platforms even by competitors, and they must make transparent their secret sauce, the proprietary algorithms that are the backroom of their businesses. And they will incur heavier taxes. Europe is ratio...