In the games industry.
People who pirate games fit into a number of categories...
- People who want to try a game before buying it - they wouldn't buy the game first no matter what, and intend on paying for it if they like it. These people are a net positive on the developers' revenue.
- People who already bought the game on a different store - they've already bought the game and are just moving platforms, you can't expect them to buy their entire library back. These people have no negative impact on the developers.
- People who are unable to run the game with DRM - there are always going to be edge cases (linux gamers, for example) that might not be able to run the paid version of a game, they've either already bought the game or never will. These people have no negative impact on the developers
- People who simply can't afford or can't legally obtain the game - there are gaming enthusiasts all over the world, some in countries where ~$50 just isn't disposable income, and there are countries where games are censored or never released. These people have no negative impace on the developers
- Others - there will always be bad eggs. But I can assure you they're a minority. Don't let them overshadow the rest.
If a pirate has a positive experience with a game and plays it a lot, they'll buy the full version for the convenience of automatic updates, achievements, multiplayer and save data cloud sync. Or they won't. Either way, the developers aren't losing money over it because they wouldn't have bought it otherwise. Leave these people be.