Forum:Equip spells or traps on opponent?

I've been iritated over and over again with almost all my opponents using Equip Spells, such as the all famous Ekibyo Drakmord, on MY monsters. My question regards to whether or not my opponent is able to equip their Spell or Trap cards to my Monsters, especially when it doesn't specifically designate my monsters. Is this a legal or illegal move? -CurZeD x