Women, contraception, and prostitution

As I write this, in April 2012, contraception and prostitution have been much in the news recently.

Contraception became a major issue on the American political scene,
as discussed here
(see also the Rush Limbaugh–Sandra Fluke controversy).

Prostitution, much to my surprise,
exploded onto the front page of the Washington Post
and into the attention of much of the political/media elite
with the Secret Service Columbia prostitute issue.

While various groups in American society no doubt
have varying opinions on the underlying issues raised by the above,
the attitudes of liberal, well-educated women seem particularly interesting.
On the issue of contraception, as reported by the media,
they seem overwhelmingly in favor of
providing free (to them) contraceptives to virtually all women,
in particular, any woman covered by health insurance.
What this seems to inescapably imply is that
it is the responsibility of everyone
to allow women to have sex with anyone they chose
without having to worry about the possibility of a childbirth as a result.
Further,
the Washington Post and New York Times seem to support that position
in their editorials.

On the other hand, the media/political complex
seems to have come down overwhelmingly harshly on
those poor Secret Service and military men who were caught in (gasp!)
hiring prostitutes to service their sexual needs in Columbia,
a country where prostitution is legal.
Yes, I realize that
there have been allegations of national security issues being at stake,
but I suspect that potential issue has been overblown,
and further note that some news articles have stated that
this has become an issue of gender politics.

So here is a question:

Why is it perfectly OK for women to have sex with anyone they want,
in fact, forcing everyone to pay to enable the sex those women have,
but not OK for men to have sex with prostitutes, on their own dime?