Food for thought on a Wednesday morning: The allure of the iPod may be so strong, says one Washington D.C. think tank, that it's leading to more violent crime because crooks so badly want to steal them.

Researchers have been struggling to find an explanation for why, after almost 15 years of annual declines, violent crime rates in the U.S. began to rise again in 2005. The key point: robberies (which largely consists of muggings as we know them) are the one area where violent crime has really been on the rise, jumping from 137 incidents per 100,000 people in 2004 to 149 in 2006. Other crimes, like rape and aggravated assault, did not increase.

Meanwhile, the number of iPods on the market during those years soared from 5 million to 90 million. This wild increase in the number of potential victims, says the Urban Institute, likely contributed to and created a sort of miniature crime wave.

Reports from various cities' police departments tend to bear out this research.

Still, there are some holes in the research and its conclusions. The greatest increase in robberies occurred in areas with less foot traffic, for example. And the number of homicides (a frequent side effect of muggings gone wrong) increased only slightly from 5.5 to 5.7 per 100,000 people over the same time span. Researchers say they would have expected a larger increase if muggings were on the rise. But the biggest question is whether it's really the iPod (and other shiny gadgets) that led to the rise in robberies. In other words, thieves might just as well have gone for wallets and watches had the iPod never hit the market.

We'll probably never know for sure, but it still pays to be safe when you're on the street and listening to your tunes: Keep your iPod out of sight as much as possible, substitute different earbuds for Apple's iconic white ones, and keep music at a low enough volume level where you can still be aware of your surroundings. And stay on the right side of the tracks, Einstein.

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