To maintain the safety of the personnel at the facility where the giant UFO is hidden, Ross just needs to give them an anonymous “heads up” before he publicly divulges, so they have time to evacuate

To whom it may concern:

I have become aware of the nature of your facility and the object that it is hiding. I find it to be of utmost importance that humanity advances forward with the knowledge that we are not alone, exceeding any personal or defense interests there may be in continuing to keep the public in the dark. For this reason, I will be publicly divulging the location of your facility and its true purpose. The reason I am telling you this is because I imagine a large crowd of protestors may begin to form around the building and I am concerned for the safety of the personnel who work there every day. Please evacuate everyone as soon as possible and keep them away until the crowd has dispersed and you feel it is safe for them to return.