greg? reporter: it is just before dawn on sunday in hong kong. people are still taking in the event that occurred just a short distance from where we are right now. a short while ago. thousands of pro-democracy activists besieged the police headquarters as well as several other government buildings friday into friday night. b& till about 15 hours and it i being described now as an aggressive new phase of this unrest. folks for the new extradition law could send their residence to some pretty shady courts and jails in china. protesters threw oil and eggs, they school graffiti on the walls of headquarters, taunted police trapped inside. the police held back in maybe it is what we avoided more violence but they still branded the action as illegal. we also watched firsthand answer activists participating in what is now described as a new mobile strategy, a