But it is certainly a popular tool today. A Human Rights Watch report published last February documented 75 cases of transnational repression reportedly committed by more than 20 countries, including Algeria, Azerbaijan, Bahrain, Belarus, Cambodia, China, Egypt, Ethiopia, Iran, Kazakhstan, Russia, Rwanda, Saudi Arabia, South Sudan, Tajikistan, Thailand, Turkey, Turkmenistan and the United Arab Emirates.

Iranian journalists in London have experienced death threats, online abuse, targeted burglaries, surveillance and even a stabbing. Chinese students have described living in a “climate of fear” while studying abroad in Europe or North America because of threats, stalking, surveillance and other harassment that they believe was overseen by the Chinese government, Amnesty International reported on Monday.

And last year Hong Kong’s leader, John Lee, said that a group of pro-democracy activists living overseas would be “pursued for life” as he issued $128,000 bounties for information leading to their arrest. The dissidents are accused of violating Hong Kong’s so-called national security law.

Why don’t governments just leave political exiles alone?

Centuries ago, sending a difficult political opponent into exile could be an effective way to squash their influence and silence their message. Today, smartphones and social media mean that a dissident abroad can communicate with extraordinary reach.

“It’s become much more possible for people who have moved abroad, whether they did so for political reasons or not, to continue to influence and be part of the public sphere in their home countries,” Glasius said.