Natisha Nodder, 37, and Stephen Ebbutt, 44, from Boston, Lincolnshire, helped Stephen Sleaford go into hiding after he stabbed Janusz Smoderek in 2011.

BBC: Janusz Smoderek

The privacy vulnerabilities that Vet and Jackson are aiming to highlight may go well beyond a few ex-boyfriends hiding in bushes.

FORBES: Researchers Show How Twitter, Twitpic Make Stalking Simple