Many years ago, a company in Canada noticed that another company was importing a substance that the first company had a patent on, and exclusive use of. They tried to find out the name of the other importer, but Canada Customs refused to name them.
So the first company went to the Supreme Court, which ruled that Customs would have to disclose the name of the other importer.
This decision became known as the Norwich Order, and today is being used in Canada as an anti-troll defense. Lawyers are using the Order to get Facebook, Twitter, and other social media sites to name anonymous posters who practice doxxing, smearing, innuendo, or straight up threatening. The lawyers can then file defamation suits against the offender.
Every country should have its own version of the law, but America in particular needs it today.