All you can really do is take precautions. One of them may be to have a seperate e-mail account for anything BDSM related - use to to communicate with people in the scene, sign up for forums and so on. One way to trace someone's internet traces is via their e-mail address. Also think common sense - never access BDSM sites at work (those internet logs *do* get looked at even if they are never acted on so someone in the IT department is likely to know what you are looking at), never give out personal details unless you absolutely trust the person involved, make sure your ID is protected in any published photographs (masks etc are useful here) and so on.

I think the tide is changing and things are getting easier for BDSM in the real world but it is still going to be a while before it happens fully (and any lifestylers in politics have to be sure to help this along if they can) so it may one day be less of a stigma.

I think the scene itself is good with regards to keeping things stum so you don't need to worry about being outed by someone at an event. The risks are any journalists who attend the events incognito in the hope of getting a scoop...

BTW, on the Mosely situation... not sure it was just the BDSM he was being done for in teh tabloids. It was also the Nazi trappings he was using for the session in question. If anyone knows pre WWII British history particularly well, you may remember who his father was and what he stood for.