Wikipedia is vulnerable. Anyone can change it the way (s)he desires. A case has been reported of an atricle on Wikipedia about a fictional character potraying as a real person. The fictional character Kane belongs to an online alternate reality game from BBC.
There has been lot of debate over the reliability of Wikipedia as a trusted source of knowledge. But the point is, such a system is self cleansing. The fact that the truth came out so quickly is good indicator of the effectiveness of the design.
Now, some argue that “The premise of Wikipedia is that continuous improvement will lead to perfection. That premise is completely unproven”. Apparently it is. But the past has shown, just as this time, errors don’t go unnoticed on Wikipedia. If someone is interested in the reliable information, just combine the discussion page with article and one will get all the different perspectives on issue of the quest.
Someone will always be able to abuse any system, or may be Wikipedia is vulnerable to abuse, but it is made by design to correct itself over the time, and that is Wikipedia’s greatest strength.