Hackers?

Well the title should explain this pretty well... I was playing on my favorite server ~Nodex~ and a couple of frap boys come on the server to hack around. I was defending the Echondrian Tower in a raid and we were winning, untill the damn hackers show up. Take a look at these pictures closely and please believe me. Picture 1.) This below is the bottom of the tower , it is inside of a 3 block tall wall that surrounds the entire tower , and it is claimed by our faction with full power. Somehow this jack-wagon gets inside and he is not using "eyes-of-ender", he is weilding his sword and was the whole time. Picture 2.) T he young man on the top is my dear faction-mate Djustin321 who was shot down , and the other one in the armour was climbing up the spiral of stairs as you can see. We blocked off those stairs further down , if you get online i will show you. Picture 3.) The guy in the diamond armour has made it to the top , how? There is a barricade before you enter the first ring. Completely blocked off with Cobblestone. And again he wasnt using eyes-of-ender , he has a diamond sword in his hands and had one the whole time. Thanks!