I completely agree with you Saddam, this is not a controlled scientific study so no conclusion should be drawn.
And Thork, microwave radiation is not ionising, it does not carry enough energy to remove electrons from atoms, molecules etc. And microwave radiation is much too large to effect us anyways. The wavelength of microwaves are around 1-10cm, our cells let alone DNA is orders of magnitude smaller than that.
Sadly enough, at school a few years ago we put ants in a microwave and none of them died from the heat, they just bundled up into regions where the microwaves just weren't interfering with.
I did like one line from the article (may have been a different article) where the girl's said something along the lines of: "We noticed when we went to sleep with phones near our head we didn't concentrate as much the next day at school".
Confirmation bias at its finest.