They didn't need to spy. They already knew and didn't care. The president held a speech in the morning, addressing his supporters who had traveled from all over the country to come to Washington. He told the crowd to storm the Capitol over the loudspeaker, and that he would lead them in doing so. He didn't. Instead he returned to the White House. But the crowd did what they were told anyway. (People do that a lot these days. They do what they're told.)