[matt1234]

A Twitter user named Jester (th3j35t3r) has analyzed Suspect Number #2's Twitter activity in the month leading up to the bombings. It seems pretty clear that there were other people involved. Check it out:

http://jesterscourt.cc/2013/04/23/boston-marathon-bombing-just-a-hunch/

[TigersEye]

Twitter user Jester found this too...

Take a look at Tamerlan's Amazon wish list and note the dates.

Terrorist #1 Amazon.com wishlist (from Jester) (FR thread)

Tamerlan Amazon wish list (the Amazon page)

I'm gonna go out on a limb and assume it didn't take a court order for Twitter user Jester to find it.

It's hard to call the FBI vetting "thorough" after looking at that and seeing his interests going back to 2006.