A closer look, however, shows that in 2005 he dabbled in two obscure stocks -- Skyterra Communications ( SKYT) and AVI Biopharma ( AVII) -- that happened to get large amounts of revenue from a source with which Obama has some familiarity: the federal government. Aside from sharing the same deep-pocketed benefactor, the two have one more thing in common. They both provide services in an area that has become a hot-button issue on Capitol Hill and with the electorate: homeland security. "Homeland Security is a field that has really sprung up in the years following the terrorist attacks of Sept. 11, 2001 , and you have a lot of small companies that are vying for a lot of big government contracts," says Massie Ritsch, the communications director for Center for Responsive Politics, a nonpartisan organization that tracks money and influence in U.S. politics. "When the people controlling the purse strings for government contracts are invested in the companies that stand to get those contracts, it definitely raises ethical questions." To be sure, it's not uncommon to find elected officials in Congress who hold investments in companies that receive federal funding or provide testimony to their legislative committees. In fact, it's hard to find any politicians with money in the stock market who aren't at least indirectly invested in a major government contractor, such as General Electric ( GE) or Boeing ( BA).