Note the corrolary though. When it's done right. David Miliband set up a blog while at the ODPM. He was criticised within the community for a number of reasons. Some were wrong (waste of Govt time, get back to work, etc - communication with those you work for is his work), but some were right.
Specifically, what happens when he changes job? Well, he now has an 'interim solution' which is to set up a redirect from his new domain name http://www.davidmiliband.defra.gov.uk/ at his new job that, um, points directly back at the old ODPM location. I've submitted the following comment, which I repeat here in full as an open letter to him:
David, the real problem here is that you're conflating two separate types of blogging.That last bit is actually possible y'know, they're not all bad this lot. Just not much good either.
As you're blogging in your job role, you need to do it as the Secretary of State, and then if you leave office/change job again, then the blog gets passed on to the next Secretary.
Ergo, domain name shouldn't be davidmiliband.defra etc it should be secretary-of-state.defra OR defra.gov.uk/secretary/blog or similar.
Alternately, if you want it to be YOUR blog, in your name, then host it elsewhere or, even better, get a central location to host all Govt blogs and keep them there rather than moving around, probably the No10 site may be best for that.
As it is, switching URLs and dodgy redirects will abound, Blogging Ministers is something I wholeheartedly support, just get it thought through as a proper strategy? Please?
Good luck in the new role. You never know, you may come up with a policy I like. Don't hold your breath though...