Comment by _jal

There are different social contexts. Everyone recognizes this; you'll say things around friends that you won't say in a work meeting.

Online communities have contexts that are just as real, but they have the digital discontinuities we all know and love, so the odds of doing the equivalent of dropping into that work meeting after several beers is much more likely and happens far more frequently.

A separate issue is preservation - of course all this is on Your Permanent Record. And the future only has very different, limited interest in what the context is now.