It's never too hard to find someone bitching about Facebook, and according to a new study, the complaints are adding up. The American Customer Satisfaction Index has released its annual E-Business report in collaboration with ForeSee Results, and Mark Zuckerberg and co. have won the unfortunate distinction of ranking dead last among users. Facebook was at the bottom in not only the Social Media category, but among all online businesses polled, which also included Portals and Search Engines and News and Information sites.

At the top of the heap in social was Wikipedia with 78 percent customer satisfaction, and YouTube came in second at 74 percent. Facebook brought up the rear end with 66 percent. The poll surveyed over 70,000 customers.

In a statement to CNET, a Facebook rep had the following to say in defense of the site:

"We take user feedback seriously, and strive to create a simple, fast, and innovative service that enables people to connect with their friends in a safe environment. More than half of our users visit Facebook every day, and we're constantly enhancing our products to offer people the best possible experience. Indeed, a report published last month by the Pew Internet and American Life Project highlighted the positive impact Facebook has had in people's lives."

Those unhappy with their Facebook lives, of course, are fueling the growth of Google+.