Then my son asked, "How come if wizards talk to Tony Blair (heh), they haven't told him to do something about the environment?" Which I thought was a brilliant question, and it leads to so many others -- why aren't the wizards themselves doing something to save the rainforests, why doesn't a Minister of Magic speaking to a Muggle Prime Minister worry about weapons of mass destruction that could presumably affect both their realms, just for starters. It isn't that I have any issue with Rowling writing allegorically about terrorism, mass murder, pedophilia or any of the other real-world concerns that pop up in the HP books: it is very specifically this sort of crossover with the real world that presses my buttons the wrong way.
I've said before that I never know whether to be comforted or disturbed by an X-Files/La Femme Nikita view of the world where nearly all evil can be attributed to a small cabal of wicked men (yes, men, as they always tend to greatly outnumber the women in such fictional scenarios). I would dearly love to believe that a Cancer Man or a Voldemort can be blamed for all suicide bombings in the Middle East, rather than an incredibly complicated series of historical, political and social factors; I would dearly love to believe that George Bush has been acting under the Imperius Curse since he took office, and that, as in HBP, a senior member of the British government has been quacking nonsense because he's been under a curse as well.
That not being the case, however, I do not want it suggested to my children that Evil, with a capital E, is carried out in the world by a hidden few while a majority of people go about their business obliviously or cowering in terror because of what leaks out in newspaper headlines. I certainly don't want it suggested that if there were wizards in the world, they might be manipulating contemporary politics without even paying attention to the issues that it would seem are of greatest importance to the Muggle and Wizarding worlds together: the survival of the planet, the care of the environment and the safety of people in both realms. We can't do anything about the fictional Lord Voldemort and the giants under his control, but bridges collapse and governments change because of human agency, decisions and errors made in full cognizance, not because some Obliviator showed up and made us commit to things we wouldn't have otherwise.
Please note that I am not accusing Rowling of carrying on a deliberate campaign of sensationalism or exploitation of public tragedy; I have no idea what her intentions were, only what my reactions were as a reader. Feel free to disagree or elaborate on an opposing sensibility, but please don't accuse me of being unfair to the author just for declaring a gut feeling about a section of her text.