The BMW Motorcycle Owners of America web site has a “FleaMarket” section. One must be a paying Member (it is a national club) to advertise or even view items.
In the past there have been problems when someone feels that they were treated poorly, or were cheated, etc. That’s human nature. The real problem arises when that individual then kicks it up a level and takes his complaint to the general membership via a rant in the discussion forums. Many heated discussions have resulted over the years, personal dissing, threats, etc. At that point accusations, directed towards BMWMOA about not “protecting” the reputation of a member (by locking a discussion (for example)) have been thrown down and it all goes to hell in a hand basket.
But it isn’t a reason not to have a “for sale” section. A clear statement of what can, and can not be sold, a disclaimer that core77 is in no way responsible for the condition, terms of sale, collection of debts, etc. is needed. The BMWMOA mods are pretty good about policing it all.