Has everything to do with PPrune not getting a liable suit.
If we could use full names... Yanni we would!
Fourplay - I'd hate to wake a few people up here, but using initials doesn't protect you or PPRuNe against libel at all.
By giving initials, you're actually making it fairly easy to identify who you're talking about (even to someone outside the company, like me). And as soon as someone is identifiable, you're in a world of trouble.
What's more, you're also taking the risk of accidentally libeling someone with the same initials.
You're kidding yourself if you think that initials will get you off the hook. You'll be in as much sh!t as if you'd written their full name in 24-point underlined red capitals.