If you are in possession of at least 500g of marijuana, you are BY DEFINITION considered to be trafficking it, regardless of intent. This has a mandatory death sentence. And here's the best part: the definition of possession is:
any person who is proved to have had in his possession or custody or under his control —
(a) anything containing a controlled drug;
(b) the keys of anything containing a controlled drug;
(c) the keys of any place or premises or any part thereof in which a controlled drug is found; or
(d) a document of title relating to a controlled drug or any other document intended for the delivery of a controlled drug,
shall, until the contrary is proved, be presumed to have had that drug in his possession.
(Source: http://en.wikipedia.org/wiki/Capital_punishment_in_Singapore...)
For example Indonesia recently executed two brazillians, and although our president keeps complaining, cut relations with Indonesia, and whatnot, the population is HAPPY they executed those two scumbags, we just wish more scumbags would make the same mistake and get executed too.
You might wonder, why is that? It is because in Brazil we have a full blown civil war going because of drug traffickers, the drug traffickers here frequently have very heavy weapons (rocket launchers, grenade launchers, mortars, anti-material fixed machineguns and rifles, they even tried to buy some small missiles once in the international black market), and are perfectly willing to use it (so our government must hand our cops military gear, literally, to handle, war-style combat, with armoured vehicles, helicopters and infantary trading heavy fire is not uncommon, and in some cities we have more absolute deaths by gunfire than the whole Iraq summed per day).
And "better society" isn't the only reason to believe in "free speech". Another reason is the moral principle that one should not be imprisoned for a political opinion.