So? No one's bringing them up on criminal charges.

If I think you're shady and you refuse to provide evidence otherwise, then I don't have to do business with you. And if I'm in charge of regulating business in the country, then I can prevent you from doing business here because of that perceived shadyness. It's that simple.

There's a decided lack of understanding in this thread about the US constitution and the role of Congress, and what this story is about. US Telecoms is a federally regulated industry. Congress does have the powers to compel testimony from individuals or companies related to this situation. If they're not satisified with the responses they can prevent them from selling into the regulated market. They don't need to engage the judiciary branch to do so.

We can argue IF this is "right" and IF these companies have been unfairly targeted, but please stop the misinformation about not having to answer to congress and requiring a court of law.

Ehh. Sort of.

Congress can investigate anything they want - the thinking is that this power is necessary to effectively legislate and conduct oversight.

The ban came from the executive branch. Nobody has a right to bring anything they want into the country. Wether you’re a citizen returning from vacation in Tahiti, or ZTE, you need permission. This ban is removing everyone’s permission to bring this stuff into the country.

Why would a court of law have to be involved? This is a Congressional investigation. Nobody is being charged with a crime.

As usual for you, you make a wild and vague claim because you have no understanding of US law and customs. In fact I doubt you have ever been to the US.