re: Did FBI Focus on Controversial Stings Distract from Pursuit of Tsarnaev Before Boston Attacks?

The question I still have is whether or not the FBI merely surveilled and questioned these particular individuals involved with the Boston Marathon bombing. As suggested by this video (from DemocracyNow!), the FBI often doesn't stop there and will sometimes coax their targets into some sort of highly illegal and/or dangerous action (so that they may then be preemptively arrested). But if a target seemingly declines to act upon whatever suggestions an agent proposes to them... they still may be inspired by those suggestions and later act alone along those lines. I find this to be problematic.

We know that Tamerlan Tsarnaev was reported to U.S. officials by the Russian government. We know that he was under surveillance at some point. And we know that he was questioned by the FBI.  But we also know that the FBI often does more than that. We know that they have supplied food, shelter, alcohol, jobs, plots, and materials to their targets in the past.  But in this instance we are to believe that they stopped short of following through with any more engaging tactics?  No attempt was made to send in an undercover operative to casually "befriend" this particular suspect?  No inciteful or provocative language was used by any such agents under these conditions? 

This is not to suggest that the Boston Marathon bombing was some sort of a "false flag" operation or that the government intended for the Tsarnaev brothers to carry out this attack.  However... I think it is reasonable to wonder about the targeted individuals whom the government has tried to incite into action but who, nevertheless, seemingly, don't take the bait.  What sort of ideas for future action might these individuals be given by government agents?  Should it ever be the government's role to suggest or promote any sort of terrorist plot -- even one that it plans to thwart?  Where would a line be drawn in these matters?  And if targeted individuals later commit terrorist attacks, after being inspired by provocative agents, doesn't the government have some responsibility for their actions?  

More information along these lines have been written about by Glenn Greenwald.  I encourage people to read his thoughts on such matters.