The Denial Industry; Is this type of Lobbying legitimate?

The other day I was discussing Exxon and the spoof Al Gore video. Today I came across an article in The Guardian newspaper (published on 19th September 2006), that exposes what it describes as the denial industry - a network of fake citizens and scientific bodies that have allegedly been funded by the oil giant to claim that science of global warming is inconclusive.

Here's the list of over one hundred organisations allegedly funded by Exxon on this website set up environmental activists.

Exxonsecrets.org

It can be argued that this demonstrates how PR is playing a central role in the climate change debate. Campaigning and pressure groups are becoming some of the most important groups with whom companies need to have open dialogue with. And some companies are buying these "groups" inorder to be seen to have the necessary grassroot support.

It also perhaps emphasises lobbying as a powerful Public Relations tool with the need to get the backing of key stakeholders in an issue. But most importantly raises the issue of the legitimacy of lobbying as a campaign tool.

Is it legitimate for corporations to pay scientists and other grass root organisations to back their campaigns against certain policies that are deemed a threat to their businesses?