When laws are bad, its bad when people face the repercussions of those laws.
Besides, it's possible that many of the users live in countries where _buying_ drugs isn't a crime, or where circumstantial evidence like this isn't enough to warrant opening an investigation. So it's possible that most of these users won't even face those repercussions.
Bad laws are usually changed because of public outrage and surprise so.......
If you know something is illegal, and it carries a fine of $1,000 and you do it, you get caught, and they fine you $1,000 you can't be like "What?! How DARE you catch me and fine me like the law says?! ARRRGH!"
Since drugs have such a stigma in the countries HNers are likely to be from, imagine if we were talking about laws against, say, women driving cars, or criticizing the president.
You'd get arrested (as expected), fined or imprisoned (as expected), then be outraged that the law exists. But you wouldn't be outraged that you _were_ arrested... you must have expected that.
I still don't get why we can't be outraged just because we expected it. If the law says I have to sit at the back of the bus, and I get arrested for sitting at the front of the bus, I can't be outraged at being arrested?
“Can be” rather than “is”. Civil disobedience can apply to laws with civil or criminal penalties (the “civil” in “civil disobedience” does not refer to the civil/criminal distinction.)
Your post seems to assume the reason for the outrage is that the arrest goes against an expectation.