Firewall rule for Niantic (Ingress)

Need help with a small problem, lately some of my employees have taking to wasting alot of time playing ingress on the clock. and while I have no problem with them enjoying their free time its starting to interfere with their work and meeting deadlines. does anyone know the urls that ingress uses for its remote queries I would like to add blocks in my firewall rules preventing office network access to the app that way they can only play on their mobile devices which will hopeful get them focus again rather then being constantly distracted.