The usual chinese propaganda - shooting videos from behind the bushes and then hyping it all over the net. Didn't we see the same propaganda with J-20.
Any country let alone China will not allow any civilian near the airport or in this case within the airport. Its a pure propaganda exercise.
Guarantee on my behalf,these pics r really taken by military fans.and sometimes they take risks on being caught by guards.
some of them even familiar with the staff of CAC.but things r not that serious in china like u thought.mostly they would be taken to the policestation,then warned by the officer and get out.maybe they would be punished of money or delete their photos.i dont know.but they wont be sentenced to jail or what.like we chinese all have an ID card and its easy for the security departmentto know our status.and we all got family,neighbour,friends and classmates.things r not that serious like 007 movies.and they all know they r just fans,not spy.
so,u may think those pics r taken by some staff chinese government,pretend to be a fans and post those pics on webs.well i think they dont need to do this.they just let it go.among those videos of J20 taxi run,we found beside CAC,there is just Barbed wire and wall block people to come in.and there r crowd of people stand behind them and watch J20.among them,passers who just passed by,farmers,people from other place just to watch J20,All kinds of.it is really hard to keep a secret.drive all of them away?those farmers wont agree,their farmland is there.
maybe its a strategy of china to "show" its new weapon in this way,but this may be also a headache for them.CAC is so famous that its hard to keep something as a secret.
compared to CAC,SAC is much more strictly. guards of SAC is not easy to come with.and that is one of the reason why CAC news is more than SAC news.some famous military fans,even those who is familiar with them,have to be careful when take photos.