So the UN has decided to re-estimate the number of people in the world who have AIDS:

The United Nations' top AIDS scientists plan to acknowledge this week that they have long overestimated both the size and the course of the epidemic, which they now believe has been slowing for nearly a decade, according to U.N. documents prepared for the announcement.
...
The latest estimates, due to be released publicly Tuesday, put the number of annual new HIV infections at 2.5 million, a cut of more than 40 percent from last year's estimate, documents show. The worldwide total of people infected with HIV -- estimated a year ago at nearly 40 million and rising -- now will be reported as 33 million.

Having millions fewer people with a lethal contagious disease is good news. Some researchers, however, contend that persistent overestimates in the widely quoted U.N. reports have long skewed funding decisions and obscured potential lessons about how to slow the spread of HIV. Critics have also said that U.N. officials overstated the extent of the epidemic to help gather political and financial support for combating AIDS.

"There was a tendency toward alarmism, and that fit perhaps a certain fundraising agenda," said Helen Epstein, author of "The Invisible Cure: Africa, the West, and the Fight Against AIDS." "I hope these new numbers will help refocus the response in a more pragmatic way."

This is an extremely important lesson, and applies outside of just the realm of AIDS and public health issues.  This same lesson needs to be learned when looking at the Global Warming Catastrophe^TM.  There are many people who will see absolutely nothing wrong with overstating the danger of something like AIDS (or global warming), as long as it means that more money is being spent, and more attention is brought to "the cause".

However, as is briefly stated in the article, this has a two fold danger.  The first is that funds are inappropriately being spent on AIDS when there may have been other more pressing needs.  The second, is that by hiding the fact that the spread of AIDS was slowing, that we were unable to look at what we did do, and do more of it.  Instead, some courses of actions which may have actually been successful, could have been abandoned, under the false belief that they didn't work.  And who does that serve?  While it may serve the interests of activists, and bureaucrats trying to get more money... it certainly doesn't do anything for those who actually might suffer.

The other danger, is that by lying about these numbers, it puts the UN's credibility (if it had any) at risk, so that any numbers they may publish on other issues (like global warming) will immediately be considered suspect.  Though by coming forward honestly now, that does at least do something to help repair the damage.