Apparently the answer to that is TENS OF THOUSANDS, or more.
IskorpitX, the tutor of an entire generation of Turkish hackers, will shortly be able to claim that he has broken into 200,000 websites. (He's currently at 191,000 according to one popular hacker watching website).
Brasilian hacker, Fatal Error, runs a distant second, having broken in to "only" 32,000 websites according to the same source.
Wouldn't you say that would make them "targets of interest" for law enforcement activity? Sadly, that is not the case. Perhaps, you think to yourself, they have only attacked "low value" websites. Perhaps they are brand new to the scene? If only that were the case! Fatal Error, who lists many US Government websites, and even my home state of Alabama government websites, among his victims, has been actively attacking websites since 2002.
IskorpitX has been defacing websites since at least 2003, and has the governments of Argentina, Australia, Brazil, China, Columbia, France, India, Italy, Korea, Malaysia, Peru, the Philippines, Thailand, Venezuela and South Africa among his many victims. Of course the US government is on the list as well (such as the National Endowment for the Humanities), as well as Harvard University and Bank of America.
IskorpitX even has his own YouTube videos!
Other Turkish "Cyber Warriors" have even done television news interviews about why they hack websites!
Here's one interesting hacker this week and the victims which are still laying around in Google's Cache:
I found it interesting because this hacker is doing SQL Exploits such as we've seen on several high profile attacks in the past including the National Institutes of Health and the United Nations. In this case, a content management system is being SQL injected to replace "titles" of things with the name of the hacker.
Google for the string "OwneD by RootDamages by FasT", and you'll find some interesting victims among the 26,100 pages being returned.
How about The Department of Veterans Affairs and their Cooperative Studies program?
(Although the Malaysian government also got a visit:
Or the Michigan Bar Association?
Systems Integrator "Regan Technologies"?
The Esalen Center for Theory & Research still has pages with the title "OwneD by RootDamages by FasT", such as:
As does Applied Robotics:
But they weren't just limited to News articles. I think I'd feel very safe using a shopping cart where every product in the online store had been renamed to "OwneD by RootDamages by FasT", such as those at MetroPole360:
But you don't have to be a business to have an insecure webserver. Just ask the National Limousine Association, or the NorWest Dog Training Club:
One subject "that comes up over and over again on Ducati Online" is "OwneD by RootDamages by FasT" according to this news article:
They're even having a conference on the topic in Brasil at the Psychology Congress. September 7th was their conference on "OwneD by RootDamages by FasT". They expected 6 thousand people to attend.
So how many websites will these hackers be allowed to deface before someone decides to arrest them?