BP has mostly failed to take advantage of an unprecedented opportunity to use social networks to at least partially blunt a public relations nightmare that started two months ago when an oil rig exploded in the Gulf of Mexico , causing a massive spill.

"They're playing by old rules," said Patrick Kerley, a senior digital strategist at Washington-based PR and crisis communications firm Levick Strategic Communications. "Dealing with a crisis has totally changed because of social media. They didn't get that."

CIO 100 listed BP has been taking a public thrashing not only for the environmental and economic disasters caused by the oil spill, but also for what some critics call a lack of honest communication with the public.

The company apparently had no strategic plan in place for using social networks to defend its response to a crisis. "It's too late for companies if they don't use social media right away when a crisis strikes," Kerley said.

BP's minimal presence on Facebook and Twitter has proved to be mostly worthless because it lacked a crisis plan. In fact, the top social networks for the most part have done BP more harm than good in recent weeks, analysts said.

For instance, a search for BP on Facebook is far more likely to produce "Boycott BP" pages -- one of which had more than 640,000 followers as of last week -- than the oil company's own pages. And a phony BP Twitter account that pokes fun at the company has more than 170,000 followers, whereas BP's official Twitter account has about 15,000.

"Companies have to realize that they need to be proactive and generate a social media audience in peacetime and let people affiliate with the brand," Kerley said.

Dan Olds, an analyst at Gabriel Consulting Group, said social networks can be a double-edged sword for companies trying to get through a public crisis. If used well, they can help get important messages out to the public. If not used well, they can badly hurt a business's reputation.

The BP affair could prove "very instructive for companies needing to handle problems like this in the future," said Olds. "I can't think of another company that has faced as big a crisis as BP since the advent of social media."