The United States Federal Trade Commission (FTC) has subpoenaed Apple to testify in their ongoing antitrust investigation again Google. Specifically, they're interested in the deal Google made to be the default search engine on the iPhone. Since Google enjoys an incredibly dominant market position in search, the government wants to find out if they're abusing that position to unfairly keep out competitors.
The introduction of the iPhone in 2007 signaled the beginning of a shift from desktop to mobile search, and from search to apps. Google reportedly pays Apple millions a year to maintain default status on the iPhone to preserve their search share, and has developed the competing Android platform to help cement their position in mobile.
What, if anything, the FTC hopes to discover through Apple's testimony is unknown. Bing, which replaced Microsoft Live search in 2009, and the now Bing-powered Yahoo! are both user-selectable options in iOS, and Apple and Google relationship has soured considerably since Android's launch.
Typically, there'd need to be a clear sign of abuse, such as bundling (refusal to allow the use of a dominant product/service unless a less-dominant product/service is taken as well). The Next Webs Matthew Panzarino offers some speculation:
Some have postulated that the deal had something to do with Apple’s desire to have Google maps on the iPhone. Two sources, one at Google and one at a company that produces Apple-competing mobile devices, have told us previously that Google licenses map data exclusively to Apple outside of its own Android food chain.
More as this develops.