Yes! I'm glad someone else has seen it. No one believed me.

lol i had this happen to me as well. I ran past a guy on a roof and he was all 'hey you stop there' and started chasing me. After he said that, a guy appeared out of him, who then said 'hey you stop there' and chased after me. And they constantly spawned like that for ages and ages, until i decided i didn't want the game to crash and hid, they lost sight of me at which point they all collectively went about their normal guard duties, bumping each other into the river and off the edge of buildings lol.
 
At first it was some real agent smith from matrix stuff though, i dropped down to the floor after the first guy saw me only to see about 10 or so guys follow me down... then 100... then even more! best bug ever

omg!!! now thats funny.

I guess it's tough living in Renaissance-era Italy.

im sorry tell us the whole story in better detail plz.. how did they get up there ?

Thats pretty awesome bug, I bet they are talking about what they think is going to happen in Assassins Creed 3.

Whoa what!?

HOW DID I MISS THIS?! 
 
This makes me want to get AC2 again just to see it!  lol  Nice find, and thanks for the documentation.  Make sure you add them to the Assassin's Creed 2 Images on the Wiki!!!

" im sorry tell us the whole story in better detail plz.. how did they get up there ? "

" HOW DID I MISS THIS?!  This makes me want to get AC2 again just to see it!  lol  Nice find, and thanks for the documentation.  Make sure you add them to the Assassin's Creed 2 Images on the Wiki!!! "

This is the only way it's happened for me: there's one specific rooftop in Venice where I ran past a guard, and right as I crossed a specific line, he started duplicating infinitely. I hadn't gotten the ten kills in one fight achievement, so I stuck around to try and get it. Well, there were just too many. I was actually pushed off the rooftop and fell to my death with about twenty other guys. Luckily, it respawned me close to the same roof, so I ran over to him, crossed the same line, and the glitch started again. There were so many this time, my 360 froze, and I haven't been able to get the glitch to repeat since. I'm not sure what causes it.
 
EDIT: Gotta' thank you for getting some pics, too. My brother thought I was making shit up. =P

Awesome 10/10
 
makes me want to jump back into the 'creed

"

So I'm searching for some codex pages and stuff, hitting roof to roof as anyone would, then I run into this odd bug:
 
 
 
 I tried to nab a few pictures with my cellphone (sorry for the quality of these) to show this off, it was pretty crazy.
 

 
 
 
 
 This was slowing the game down to probably 3 FPS unfortunately, so it was barely playable. Interesting though all the same.  Anyways, It's hard to tell from the pictures but these guys were doing a Jonestown-esque mass suicide from the rooftop, it was dramatic but really topped off the experience
 
The following might be considered graphic and not suitable for children:
 

        Well now I'm going to try to deal with the 3 FPS and loot these jokers. Doubtful I'll be able to get far with it, it's sooooo slooow. "

The guards are pretty casual about their mortality when they stop chasing you, it's more than a little odd...

boy it's amazing what you can do with a pc and console commands huh!

" boy it's amazing what you can do with a pc and console commands huh! "

Hooray for mass suicide!

" @VisariLoyalist said:

" boy it's amazing what you can do with a pc and console commands huh! "

I apologize I see the buttons XD don't rage on me "

" HOW DID I MISS THIS?!  This makes me want to get AC2 again just to see it!  lol  Nice find, and thanks for the documentation.  Make sure you add them to the Assassin's Creed 2 Images on the Wiki!!! "

Haha, nice.

lmao that would be so freaky to see if you're playing that game in the wee hours of the night. then the power goes out! fuckin shit bricks.

Pics or it didn't happen. 
 
Oh.... 

That's a really cool bug. The only bug I had was falling through the world and finding myself underneath it all. I was in a pool of water and could swim forever all the while looking up at the city, of which I had fallen through, in the sky.