Everyone has friends and enemies online, but what do you do when people online are threatening to kill you? Well-known Icelandic women’s rights advocate Hildur Lilliendahl Viggósdóttir faced this problem last month when she came across the following message on Stefán Heiðar Erlingsson Facebook wall: 'If I "accidentally" ran over Hildur, she is probably the only person on earth that I would back up over, and leave the car on top of her with the hand brake on!!! Put this in your "men who hate Hildur" folder, Hildur Lilliendahl'.