I think this could be a kind of negative propaganda from Mainland people to cause more panic, as I guess is the way they do there. I admire the courage from HKers. It is to sad to see how they are attacking universities. Unbelievable!
In addition, I read other post mentioning the main reason to attack CUHK was with the intention to take control of most of the internet services ; as it houses the Hong Kong Internet Exchange. It was circulating just a day before the one and mentioning here in my post...
I also think it will be difficult to control every single communication.

So sad all this chaotic situation!