Twitter isn't the only party that thinks merging Google+ with Google search results is an abuse of its monopoly power in search.

Privacy watchdog EPIC filed a complaint with the FTC on Thursday, saying that Google is using its search engine to create an unfair advantage for its social network. The report says Google is highlighting results from Google+ at the expense of pages that might be more relevant.

"For example," EPIC executive director Marc Rotenberg wrote in a letter to the FTC, "the right-hand display of notable business and Google+ users replaces highly-visible advertising space, even for consumers who have no Google+ accounts and are not logged in to Google."

The letter cites research by Harvard Business School professor Benjamin Edelman, who has found more than a dozen Google services receiving favored placement in Google search results.

"Some have developed into solid products with loyal users," Edelman wrote in a blog post. "Others are far weaker. But each enjoys a level of favored placement in Google search results that other services can only dream of." (UPDATE: As a commenter pointed out, Edelman has done consulting work for Google-competitor Microsoft.)

When Google announced changes to its search engine on Tuesday, Twitter issued a statement calling them "bad for people." Twitter general counsel Alex Macgillivray tweeted an example of a page he felt demonstrated the new system's inefficiency. The page showed Google search results for the search term "@WWE" that didn't even include the organization's Twitter page.

These results were different than those returned since November, because they included a list of Google+ pages related to @WWE in a right-hand column. Because Google doesn't index the "@" symbol, they are the same results that "WWE" would return.

About 24,900 people have +1ed or added WWE to their circles on Google+ — but 792,642 people follow WWE on Twitter. Macgillivray's point: that the WWE's Twitter page is a more relevant social source than its Google page and should be represented as such in Google's search results.

Twitter ranks higher than Google+ for the WWE in Yahoo, AOL and Bing results.