Full disclosure
It's also important to understand the nature of IT hacks, no press dinner or beer session would be complete without some journos telling vendors how to run their firms, a small % of which actually gets used.
It's just this side of impossible to make a living as a pure freelance IT journo and most have sidelines, indeed the fact that I've written code for many firms you've heard of and have done IT to banks make some of my stuff more credible (or not; you choose).
Also if you're a specialist in (say) firewalls or C++, there simply aren't enough paid articles to be written.
Although the Reg is a mighty organ, the openly published sector is small compared to in-house publishing, marketing, etc. All big vendors of most types of stuff churn out piles of glossies and usually pay rather better per word or time than journalism, this being so common, I doubt if any long time writer hasn't done at least some. (I did some for IBM).
So many like me have a day jobs and this is where grey areas get murky.
As an IT director, I got so much personal grief from Oracle when they helped get my boss sacked then went after me, that I can't ethically ever take a commission to write about them. But whose ethics apply here ?
I don't like Java, never have, even when it was a Sun product and have made far more from MS based products than any other, does that make me a shill ? If I told you I got paid some years ago to teach some cruel & unusual programming at M$ years back, would you change your mind ?
Even if my NDAs allowed me to list who I've done stuff for, would you honestly bother to read it all ?