Interesting comments. For what its worth, my two penneth:
1) Pprune, like any group or cross section of society, will attract its share of idiots / nutters / people you wouldn't want to sit next to on the bus. You can either ignore them and wait for them to get bored and go somewhere else or, if they are persistently offensive, kick them out.
I think the moderators do a great job in knowing where to draw the line, and some of the loonies are worth having here for a laugh (try searching ronchonner's posts).
2) The site does a fantastic job in educating, supporting and encouraging wannabees like me, and I'm sure that without this resource I'd still be happily driving fs2000, rather than jumping into a real C152 and trying not to bust the London TMA.
In short, this site is a huge benefit to a huge number of people, and out of 30,000 odd members, you'd be doing well to find more than a dozen or so that you really couldn't live with.
There, sermon over & back to sleep.
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Looks like I picked the wrong week to quit pruning.