For example:
I'm not a fan of DRM, but there's nothing preventing anyone from downloading the game and selling/giving away copies with ease.
Actually, WebGL games would be a lot more secure from piracy, because they would be online, and you could easily stop 99% of the piracy by requiring a login for the game. It's basically like the Diablo 3 model, only better. Because Diablo 3 should be easier to crack and play on private servers (not sure if even that has happened yet).
Making an "online game" instead of a native "PC game" is the best way to stop most of the piracy.
In addition to that, just cracking the Diablo 3 client isn't enough, because a lot of the game logic runs exclusively on the server. For example, even with tens of thousands of test runs of a specific monster, you still won't know the correct item drop probability table, because that table is never sent to the client. Only the result of the server-side dice roll checked against the server-side loot table.
Moot point. Any client software can and will be cracked, regardless of how difficult it is to crack. Which is mtgx's point - online games are easier to secure because you can put logic and validation on a remote server. No DRM needed. Your example of Diablo 3 only proves his point. It's not the DRM that makes Diablo 3 hard to crack - it's the server side logic and validation.
The piracy while a legitimate problem is a relatively minor one. The first is visibility, the second is quality. Getting to the point where someone bothers to pirate your stuff and the majority of people that download it install it and play trough it is a mark of success - doing something right.
And with sizable proportion of the gaming community in their 30s - you will be surprised how many people have desire to support the studios. We learned our lessons with Shadow of the colossus, Psychonauts and the fate of Black Isle.
On the other hand, the VM cool kids of today might have an issue.