Personally, I think that this is exactly the right time. Perhaps not "preaching", but it deserves some serious thought.
In Iran, there was a big earthquake. At the moment, they've counted at least 40 people dead (with the fear of that figure being a lot higher). This isn't an attack so not caused by humans but it would still be interesting to see how the media attention compares with the attention given to the storms in the New York area recently.
There's no thread started on the Iran earthquake and I would be willing to bet that if a massive earthquake like that happened in LA or the UK or so, it would have a thread. So, exactly on this day, I feel it's the right time to talk about bias and hypocrisy involved because it is happening right now.
In Syria, people are currently living and dying in horrible circumstances and the news about Syria is spread as if you're talking about the price of 1 kg of oranges.
Perhaps this is exaggerated but IMO, not by much. This involves lots of innocent people and nearly nobody gives a damn, by the looks of it.
Not to say that what happened in Boston is not horrible. Of course, it's terrible. A marathon like that should be a joyful event, a celebration of life.
But on a day like this, when you compare what happens around the world and just how much more importance is given to the US drama, it leaves a sour taste in your mouth.
This is a board populated by Western posters in Western countries. Do you think that people in Western countries are better able to relate to things that happen to Americans, or things that happen to Iranians and Syrians?
People are more emotionally affected by stuff that hits closer to home. It's human nature and has nothing to do with media bias.