A real easy way to get this Trophy / Achievement is to use a Fast Transport and go to San Marco, Venice. (Using the Fast Transport is very important.) As soon as you get to San Marco you see a group of guards. One of those guards is a brute with a Long Weapon. Kill him and the other guards. And pick up the Brutes weapon. To the north there is a building thats in a restricted zone go to the west side of that building there should be more then ten people there. Make sure you still have the Long Weapon. (Its really called a Pike.) Get all the guards in the area on you, When all of them are on you drop a Smoke Bomb. When you use your Smoke Bomb your going to drop the Long Weapon. Once the smoke bomb goes off pick up the Long Weapon and look for 5 guards that are close together. Get in between them and sweep                             (You learn how to do this at the Training Ring at the Villa)  Now it should say you got the                      Sweeper Trophy or (Achievement) Trophy = PS3 / (Achievement = X-Box 360).  Now that you have that KIll guards tell the Smoke Clears then, drop another Smoke Bomb. Keep killing guards tell it says you got the No-Hitter Trophy / Achievement. If it says Trophy then It means your smart for buying a PS3, if it says Achievement..... For Shame... (Just Joking!)