If you want to see how it is really done, look at Russia - people that have money get charged with money things. You have tax audits, labor laws audits, financial compliance audits, whatever. With 2000-page laws and over 50 new federal crimes added to the statutes every year, I'm sure if you need it you can find it. I'm not saying Obama is there yet - I really hope not - but the technology is there. Nixon was impeached in part for using it, and Obama could use it too and there's some evidence it is being used here and there, even though no evidence yet it is used systematically by the highest branches of government. But it is there, and it works.
Whose to say they would pursue those charges? Why do they have to even disclose why they nabbed them? Under the PATRIOT act they can make anyone disappear without justification. Obviously if they're committing treason they could figure out any number of ways to make it happen.
Julian Assange is pretty high profile, considered a journalist by many, has run an organisation that exposed many legitimate scandals, etc. Celebrities also go to prison quite often.