On February 24, the hacker collective Anonymous declared cyberwar on Russia, claiming that it was targeting state TV stations, government ministries, and banks in a series of retaliatory strikes for Russia’s cyberattacks on Ukrainian government websites and businesses. The term “cyberwar” may have sounded like hyperbole, but international legal experts tell Rest of World that the volunteers joining the effort to attack Russia in cyberspace may, legally speaking, have made themselves into active combatants —  and legitimate targets for retaliation. They could even unwittingly find themselves complicit in war crimes.

The Geneva Conventions, the laws that govern the conduct of war, were established in the aftermath of World War II, and, although they’ve been updated and amended since, they didn’t anticipate that cyberspace could become a theater of conflict. The gray areas left by that omission means there are conflicting interpretations about what war crimes might look like in cyberspace and who is accountable when they happen.

“We still have no clear single, common legal interpretation of how the Geneva Convention applies to cyberwarfare,” said Nathaniel Raymond, a lecturer at the Jackson School of Global Affairs at Yale University and an expert in technology and human rights.