Most will tell you that if you leave them alone, octopi will leave you alone. An octopus rarely ever goes on the attack, especially against humans. They can be territorial though, so getting too close might cause this. Other times, they might be a little angrier than humans expect. The man above experienced this the hard way. An octopus was not happy with him being there and decided to attack him, taking away his camera along the way. Must not be a fan of being put on video without permission!