We don't yet know the cause behind the Boston bombing, it is possible that it is one person who had a grudge against the race.
But more likely, someone with a political/religious cause.
Whatever it is, it is almost certainly a pointless waste, just cruelty without any just cause or any reasonable expectation of any change in policy.
Let's say that the bombers are Muslim with a grudge against the U S/Israel. Maybe they had family members killed by one of our drone airstrikes.
But this bombing, like so much of violence does not specifically target those who did these airstrikes, it only targets the public at random and even more so it will not make any lasting change in U S policy or practice.
For no real gain for whatever the cause is, they were willing to kill an 8 year old child. There can't be many things more wrong than that, no matter what being or persona you believe in.
I remember the Timothy McVeigh case. He hated the FBI, and with some just cause, for at Rubey Ridge their snipers shot a dog belonging to a 12 year old boy,shot his Brother in the back, and the next day shot his unarmed Mother while she was holding a baby.
But in trying to target them, he blew up a bunch of children in a day care center, much worse than any wrong done by others.
There are some good things in our world, but as a society we still have way too much addiction to violence and cruelty.