The Tsarnaev family, including the suspected terrorists and their parents, benefited from more than $100,000 in taxpayer-funded assistance — a bonanza ranging from cash and food stamps to Section 8 housing from 2002 to 2012, the Herald has learned. “The breadth of the benefits the family was receiving was stunning,” said a person with knowledge of documents handed over to a legislative committee today. http://bostonherald.com/news_opinion/local_coverage/2013/04/tsarnaev_family_received_100g_in_benefits

See also:
People get angry
“There was such ignorance in the Bush White House about Islam and about the history of so many disputes that exist in the Middle East. People get angry. They lash out.
It’s the whole squalid intervention that has disfigured the record of the Western democracies. I think this fuels the anger of the young men, who, as we saw in Boston, went out, and, out of anger and demand for revenge, claimed lives in the West.” http://www.bbc.co.uk/news/uk-politics-22352929