That’s what I was thinking. If I work for an NGO, and my personal opinions correspond to the positions they advocate (as will generally be the case), is any opinion I post here in my free time secretly a way to promote their agenda? I don’t see it that way.
We should keep in mind that not all (probably not most) NGOs are advocacy organizations. For example, many provide services to the public (usually those that the government is failing to do).
To further clarify the definition of “NGO,” it is an internationally used term. In the domestic U.S. context, we would generally call them “non-profits.”