evidence posted on social media is far from perfect. People recording atrocities often lack expertise or may be partisan and thus film selectively. Prosecutors and judges may worry that footage has been staged, manipulated or misattributed. These worries will further increase, as it becomes easier to get computers with artificial intelligence to make “deep fakes” or highly plausible audio and video forgeries.

Yet because it is difficult and dangerous to gather evidence in war zones, such footage may be all that prosecutors have to go on. At the very least it can provide new leads, or help to corroborate eyewitness reports and other evidence.