I am currently in mainland China and due to leave out via Hong Kong on Thursday night, it will be very interesting to see what, if anything has been done to "beef" up security. I have a colleague flying over this way arriving tomorrow afternoon local time, so I'll be intruiged to find out his experiences.
To be honest the current security in place at the airports I've used over here is as good as I see in Europe, except Turkey where you have to put your bags through a scanner before you even enter the airport building due to it's proximity to the Middle East.
Obviously, this is big news over here at the moment and there is a lot of frustration over the perceived lack of information, but the airline is caught between a rock and hard place right now until clues start emerging.
Bottom line, we all suspect that the plane has suffered a catastrophic failure/incident mid air due to the fact that it simply fell off the radar and there was no communication to say there was a problem. From my perspective, the fact that there are reports that the plane may have turned back without any communication at all is worrying. If it hasn't then where the hell is it?
As for the cause, everything is pure conjecture at the moment, meaning nothing can be ruled out. For all we know it may have even been shot down. Until the recorders are found and reviewed we will not have a clue.
I just hope that they find out something sooner rather than later as the poor families must be going through hell right now!