Earlier this year, Eric Jackson, investor activist and blogger, played a major role in fomenting a shareholder revolt that led to the resignation of former Yahoo CEO Terry Semel. Now Jackson is at again as he calls for the resignation of Motorola CEO Ed Zander after Motorola issued a warning that it would report a second-quarter loss, and lowered sales forecasts. According to Forbes:

“On Monday, Jackson posted a YouTube video message on his blog Breakout Performance to his fellow Motorola shareholders with a five-point plan on turning the company around. Replacing Zander was at the top of his list.”

[kml_flashembed movie="http://www.youtube.com/v/DmEBDUrYrYs" width="425" height="350" wmode="transparent" /]

Clearly, the game is changing (as one comment on YouTube notes) when shareholder revolts are carried out, and apparently with great effectiveness, through blogs and YouTube video. Apparently social media has grown up and corporate America needs to understand what it’s all about and put in place blog and video strategies of their own, particularly in executive communications.Motorola will report earnings July 19, so quiet period regulations most likely bar Zander from recording a video in response to Jackson, at least for the next seven days. It may be too late for Zander, I don’t know, and truthfully, the man shouldn’t be judged on whether he records a video, but on his performance as CEO and whether he’s fulfilled his obligations to shareholders. Arguably, though, Zander can either respond, which might serve to validate Jackson’s clout with investors, or remain mute, possibly telegraphing that he doesn’t have a strong response to the charges.