WRONG...what the constitution protects US from it use of information in a criminal trial without a warrant to gather that info.
The administration is not going to court with the info gathered, or trying to prosecute with the info gathered, rather they are using the info to stop, or interfere with the process of foreign nationals [or U.S. citizens who have ties to foreign nationals] who might be planning to bring harm and/or chaos to the the U.S. people or their properties.
It's not only the Constitution (which is not limited to criminal prosecution), but also additional laws passed by Congress specifically to keep US agencies from monitoring/spying on US citizens.