What can I do?

First of all, one big thing I can do is volunteer service. And while maybe not SOCO, because I really don't know how to contact or volunteer with them, there's always things like soup kitchens or cleanup services that could indirectly influence those in cage-dwellings. However, overall service to the community is a good thing anyway while not directed to these people and is a viable option. Second, there's the possibility of getting to know one of these people and establishing a friendly relationship with them, since friendship would probably be a positive thing for people in cage-housing, but this would be extremely challenging because it's first of all a little difficult to befriend strangers and I don't know a single word of Cantonese. Therefore, I think the best option is just volunteer work, as it gives a more organized sense of assistance to those in need.