wiki entries - vandal?

I created a wiki entry in wikipedia for a company as 'open source' info. In the next couple of days I notice that the info on the company is editted by some one in the company - perhaps by getting paid for making this entry from the business.

I tried to put back couple of points that are not exactly in favor of the company and the corporate folks would come back and delete my entry. This incident makes me wonder, if we should really make it open for any one to change.... How to free the 'open' from folks who have $$ interests - point of view.