This is the order of events:

1. Eman Abdelhadi, an activist and professor of sociology at the University of Chicago, tweeted: “Oh Kamala is NOT ready for Chicago. But don’t worry; we’re ready for her."

2. Some people on twitter thought that this was a threat and called the feds.

3. A single FBI agent called Eman and asked her if she intended to hurt the democratic nominee to which her lawyer responded "no".

That is literally all that happened.