Sometimes we can dismiss social media as an annoying online portal for excessive selfies and a multitude of angsty teens and trolls. But then it does something amazing and we shake off our cynicism.

In January 2008, Jonny Benjamin had just been diagnosed with schizoaffective disorder and was set on ending his life. He sat on Waterloo Bridge, but didn’t jump. Neil Laybourn intervened, talked him down from the ledge and told him "you can get through this, you can get better". Words were exchanged, and Laybourn saved a life that day.

This month, Benjamin began a Twitter campaign to trace down Laybourn using the hashtag #findmike. After thousands of tweets and the hashtag going viral on Twitter, Laybourn’s fiancée saw the campaign and the two men were reunited this week.

Benjamin, who is a video blogger and has presented a BBC Three documentary on mental illness, is currently making a documentary about his search for Laybourn and how the campaign on Twitter worked. The film could be released as early as spring.

It is easy to forget how incredible social media is; we can now communicate faster than ever before, and it has made our world so much smaller.