This is the great mystery of it. Normally the gimmick is trying to convince everyone he's NOT a 5ft midget who fantasizes about being a hardman. Darren's broken the mould in this regard. I genuinely hope he's real because he's a good laugh, but it's starting to look like he may be the alter ego of a elusive reclusive Iranian, criminal mastermind.
Yes, you would think a 30 year old dwarf, working in a supermarket and who requires steroids to achieve the physique of a bricklayer would be the first person to lie about their life over the internet. However, Darren is honest about all this. He even uses his real name apparently.
Sometimes gimmicks are used as props for other gimmicks, to enhance credibility. See OMR's treatise above. DA is rather sloppily supportive of Joon, and maybe has an "IP problem", where his originating IP address matches another's login. In these cases, the board feels compelled to act.
Does Darren show any real support for Joon? I can't recall him posting any comment that was non related to his usual interests.
Gimmicks usually are quite easy to spot. They will have similar writing styles and opinions to another poster such as the example given earlier by 1MR. Darren's posts however seem to be quite unique here.