I am a recent college graduate who has applied for entry level positions with the CIA, NSA, and other organizations.  I have no criminal background and I have not recently used illegal drugs.

I have, however, maintained subscriptions to several pornographic websites for the past several years.  The content of these sites is not illegal.

I will mention that I have been in a monogamous relationship for about two years, and that my sexual history, aside from the above, would not raise any red flags.

Will my use of pornography become known to the agencies to which I have applied, and might it lead to my exclusion from employment in government intelligence?

LOL...well, if you're worried about something as "minor" as this, I'm sure you don't have anything to worry about as far as being denied for a clearance.  Usually the people who haven't done anything really bad, worry about minor, minute, things that will have no bearing on their security clearance unless they lie about it.

The issue might not even come up.  And I doubt they would somehow find out anyway.