There's two things at work here, and they're not necessarily the same thing:  what's legal and what's ethical.  In your drug example, China, India or Cuba mass producing a drug that's too expensive for them to buy may be the ethical thing to do, but it's still breaking international patent law.

To give you a flip example from the business world, I'll give you a case study from the startup Callpod and their dealings with Target:  Callpod produces a universal charging device called Chargepod, which has become a big hit.  Attempting to increase distribution, Callpod seeks a deal with Target in order to nationally distribute the Chargepod, but the deal hits a snag, but eight months later, a clone of the product, being produced by Target themselves, appears in their stores.  Callpod, which was smart enough to file a number of patents on the Chargepod technology, sues Target, who never had any real desire to sell the original Chargepod in their stores, and wins damages.

Target behaved illegally and maybe immorally in this case, but every move they did was the right move from the business perspective.  They knew that startup companies aren't usually the best at defending cases of patent infringement.  Most of the time, they don't pursue any civil suits, and if they do, they hire inexperienced lawyer friends who get beat in court.  In this case, Target was wrong, but more often than not, they would be able be able to sell the product without having to pay any of the licensing fees or any negative repercussions.  And even in this case where there were repercussions, they weren't enough to damage, or even noticeably dent Targets earnings.

When you download files off the internet, you're behaving like Target:  you may have virtually no chance of getting caught, and are gaining access to tools you wouldn't otherwise, but it's still copyright infringement.  Spare us the rationalizations, and have the balls to admit that you're doing something illegal, even if you won't get caught.