RAF has issued a list of directions for pilots flying anywhere through South East England during the Olympics. RAF Eurofighters Typhoons constantly flying over the areas above will intercept your aircraft. If Typhoon joins on left hand side of your aircraft and rocks wings, then rock your wings and follow Typhoon. The same is true if you get intercepted by a RAF helicopter, which will fire a green laser at you or release flares at night. The RAF is in full alert, ready to intercept anything that flies off their planned path or into prohibited air space.”]
Source: https://gizmodo.com/raf-typhoons-to-aggressively-defend-london-during-olymp-5899473