I mostly agree with what sgdiehard has said so far.
Anyway that's the reality of things. Non payment of works done is,
IMO, a very common practice, especially in the building industry. I
guess most of us are too used to paying things upfront, like
shopping in a supermarket. Or paying for utilities, with the threat
of it being cut off.
It's a matter of integrity. Size matters. Contractors run out of
business on a near daily (not actually a known fact, just a figure
of speech) basis because larger companies allow lawsuits to drag to
a point where they run out of business. you see, they are being
paid for their works *done*, not what they're going to do. it's an
opportunity for non-payment; where the money goes eventually
depends on who's holding on to the money.
It's a dog eat dog world. 2 wrongs don't make one right, but they
dont' necessarily prevent a 3rd or 4th wrong either. nobody has to
get used to it if they don't want to, and i guess it's a right to
exercise their views, whether on national tv or in sgforums. but
like what sgdiehard said, lip service is cheap.
I know for one, i'd rather not do anything about foreign workers;
it's nice and all to be doing something for them but really, it's
way down on my priority list. I don't have a very good impressino
of foreign labour's conduct in singapore,
their idea of festivity dosen't quite coincide with mine. take a
walk down orchard road on New Years, and you'll see what i mean...
where they gather = girls being molested.
If anything, we should probably id-tag them. 
Anyway, I'd rather fight for singaporeans being treated with higher
equity in terms of works done and payment elsewhere.
No intention of picking off where sgdiehard left. but really, for
anyone, whether if you're an activist (hrrhrr) or a lawyer, who's
thinking of doing something, and 'getting off your armchair',
do something for your fellow countrymen instead!
keep your frontyard clean before your backyard!
seriously...