The list of girls to protect had gotten so long.  With two Prefects, Evans and Lupin, in the loop, it helped.  After a bit of discussion and a method to hide and lock the maps, Reggie and Siri copied the Cockblock Snape Map (Siri named it) for each person.  Siri also developed a way that the five students could communicate through the map to coordinate their rescues.  They could write the group or an individual at will.