As per the data collected by CERT-In, a government agency of the Indian Community for responding to computer security incidents as and when they occur, reported that a total of 1981 websites were defaced in the first three months of 2010.

Website defacement in general is a kind of an attack by hackers that changes the visual apperance of a web page or replaces the real webpage of a website with their own.
Comparing the results with past trends, I am not really surprised at these statistics since the number of defacements are growing at a consistent rate. The fact is that hackers are becoming more sophisticated by the day but website developers or IT managers are probably still considering security as an afterthought, the reason why there is a growth instead of a decline in such attacks.
The only viable solution as I could see is a little more training and awareness for developers & IT managers and help them realize the potential benefit of taking security as a higher priority.

More defacement statistics can be found over the following link: