Ok, I don't know if anyone else has ever done done this but I have countless times. I cast negative nano spells such as "Lesser Blizzard Red Tape" "Ransack Skills (major)" and others on myself! when I really wanted to put it on the enemy! I target myself to heal, and usually forget to target the enemy to put the spell on, and mind you, some of these guys are tough to take down making it even worse if I'm damaging myself in the progress lol. I think that negative nanos (intended for enemies) should not be able to be cast on yourself!