There are two ways you can tackle piracy: the way that doesn't work (threats, control and lockdowns) and the way that does (offering a superior service to piracy).
Paradox, publishers of games like Crusader Kings II, Magicka and Cities: Skylines, are fans of the latter, and it's refreshing to see that their approach appears to be working.
Here's Paradox's Shams Jorjani talking about his company's piracy plans in the days immediately following the release of Cities: Skylines:
That last one touches on what might be the single most important factor in this: Steam. It's Valve's service that lets games update automatically, and it's the Workshop built into it that lets modders enhance a game's core experience to the point where it becomes too tempting for pirates to bother pirating (which is exactly what's happening with the very moddable Skylines).
But still, hats off to Paradox for being one of the companies (Riot are another prominent example) who tackle the issue the "nice" way, and are seemingly happy (and are being rewarded with sales: Skylines sold 250,000 copies in two days) for their approach.
I'm one customer who can vouch for it: alongside constant DLC for their titles (which is often pretty cheap), Paradox also ensure that major updates and changes are also introduced via updates and patches. The result is that there are Paradox games—my experience being mainly with Crusader Kings II—that can become almost unrecognisable from their "vanilla" iterations by the time they've had a year or two of updates, and that gravy train of progress is more than worth what they're charging.