Two can play this game.
The second war had just begun and Harry was already getting tired of the so called 'war'. If anything had actually happened thus far then he might have felt differently, but as it was, both sides were waiting for the other to make a move.
If Voldemort went out into the open, then the ministry would be forced to act. So he waited.
If Dumbledore did anything, then Fudge would have him in Azkaban faster than he could say 'Dementor'. So he waited.
Both sides were content to wait, but Harry wasn't. He was getting the brunt of the abuse in the whole 'Voldemort is back' saga. The media saw him as either a spoiled attention seeking brat, or as mentally unbalanced. Neither appealed to him. Those in the school mirrored the sentiments of the prophet. And then there was Umbridge...
The people needed to get their collective heads out of the sand, and one day in detention – while carving letters into his flesh – Harry had a most devious of plans. The hat wanted him in Slytherin, and this plan was worthy of his house.
So bloody simple.
Just need the headmaster and a few of his order friends.
The next day the entire front page of the Daily Prophet showed a full page spread on the return of Voldemort. Half of the page was allotted to a picture of Voldemort walking down Diagon Ally shooting the dark mark into the sky. The man was flanked by half a dozen of his Death Eaters.
The tide of public opinion instantly turned.
Harry was seen as a hero and was praised for speaking out amongst great public pressure and disbelief.
Dumbledore was once again seen as the bastion of light.
Fudge was exposed as the bumbling idiot he was. His and his staff cleaned out their offices after a rather close vote non-confidence in the wizengamot.
Voldemort and his merry band of men were left scratching their heads.
The dark lord never left the Malfoy estate!
He had an alibi! Bullocks! Can't exactly go to the aurors and say, "Hey! It wasn't me that was in Diagon Ally!" That just might tip them off to his existence.
The dark didn't get to have their head start, and it was very easy to accomplish.
A few black cloaks and masks for the death eaters, and a pink haired auror who had a real talent for changing her appearance was all it took.
Hey, if a death eater could fool an entire school and one of the most powerful light wizards in the world that he was the Mad-Eye Moody, then who says that the other side couldn't use the same tactics?
The sheep who called themselves wizards believed it. There was a picture and it was printed in the prophet, thus it must be true.
But then again, wizards are stupid.
