suspects behind the boston marathon bombings , which killed two women and a young boy , and injured a further 264 .
but in the days after the 2013 attack , the users of the subreddit , find boston bombers , hurled false accusations at countless spectators who had been wearing backpacks at the high-profile event .
their claims - based on the analysis of photos and videos of the marathon - even led to 22-year-old sunil tripathi , a brown university student who was missing , being wrongly identified as the bomber .