Allstate Foundation's Purple Purse initiative is highlighting the financial aspects of domestic abuse with a "social experiment" in which unsuspecting taxi riders find a lost purse containing a phone with some horrifying messages on it.

The campaign, by MSL Group Chicago and Leo Burnett, shows the people picking up the phone which is being bombarded with increasingly unpleasant and abusive texts, about how the partner is going to prevent her from having access to money. Eventually, the phone rings and it's apparently the purse's owner, who asks them to come and hand it over in a nearby cafe. The film shows how concerned the strangers are for her welfare, and ends by encouraging others to come forward if they suspect an abusive relationship, and to come to Purple Purse for advice.

The film was directed by hidden camera expert Andrew Lane at Rival School Pictures. It was released as Allstate Foundation Purple Purse today announced Serena Williams will serve as the program's new ambassador.