At the Boston marathon, an Arabic looking man is spotted in the crowd with a backpack, in another pic, his backpack is missing!?

I looked at more pics, of this man, and now have second thoughts.

When you compare this man's location, to the actual location of the bomb, which is much closer to the finish line. You'll see, he's still quite far away from this.

Here's a another pic, that gives a better idea of where this man is at (he's toward the very bottom of the pic) and quite far away from the finish line
[link to cryptome.org]

Here's the location of the bomb explosion, which is much much closer to the finish line
[link to www.flickr.com]

Also you refer back to this pic
[link to cryptome.org]

You see a tremendous amount of more people, which now makes it more probable that another individual could of had a similar bag / strap.

The FBI probably took em.. lol

I looked at more pics, of this man, and now have second thoughts.

When you compare this man's location, to the actual location of the bomb, which is much closer to the finish line. You'll see, he's still quite far away from this.

Here's a another pic, that gives a better idea of where this man is at (he's toward the very bottom of the pic) and quite far away from the finish line
[link to cryptome.org]

Here's the location of the bomb explosion, which is much much closer to the finish line
[link to www.flickr.com]

Also you refer back to this pic
[link to cryptome.org]

You see a tremendous amount of more people, which now makes it more probable that another individual could of had a similar bag / strap.

you mean photoshopped them?

Dude has earbuds. Getting instructions?