FYI: This submission is just some images pulled off a thread of idle speculation that somebody posted to Tumblr. It's not some kind of organized campaign claiming to have found the people responsible.
1. assemble the pictures
2. give sources for their pictures (an imgur link doesn't count)
3. show what evidence they think that makes the person a suspect
4. submit it to the FBI
5. not post it on the Internet
Posting it on the Internet doesn't help. The FBI will need to track down original photos, and being duplicated everywhere on the web, with a bunch of other people photoshopping comments on it in various ways, won't help their efforts.
The FBI only needs to see it once. This isn't voting. A bunch of people submitting something doesn't make it more likely to be true, or more likely to be listened to.
On another note, it's funny how people tend to focus on people who stand out, like the guy with the white baseball cap. He stands out in a sea of dark colors, so of course people focus on him. It's very hard to believe (although possible) that the actual bomber would wear clothing that makes him stand out in any way.
This is bad, and very wrong.
No, actually. We average out to the same kind of mob-prone mooks we like to tut-tut at others for being. Except our mobs are about standing around going "Well, actually..." and that's marginally less puerile than what we see from 4chan mobs.
It might feel like skepticism, but from where I sit it looks a lot like pretentious pseudo-intellectual grandstanding. It's like hanging a somebody's napkin doodle in an art gallery just so you can complain that it's not the Mona Lisa.