It is actually pretty amazing - see the screenshot below for what was trending just now in Manila.
But, aren't we missing a whole lot of information? Apparently nothing has been trending recently in the whole of South East Asia. Despite the fact I just watched a bunch of tweets from friends in Singapore/Thailand/Malaysia/Indonesia just scroll by. Hmmm.
It is a nice experiment, and a good start, but big gaps like this will inevitably raise the question whether any of the information can be trusted.