Hmm, some of us in the EIM are in their 70’s and we know enough to not make that kind of blunder (at least, I think most 70+ EIM members know that!).
Also, I tend to think that most of the IM posts really were/are JK, although there are some that make me wonder if he lays his phone down and wanders off, without logging out of COTH, And LK picks up his phone and makes a quick ranting post using his login persona.
And as far as alternate accounts - some email providers allow users to create up to 5 different email addresses. I can totally see how LK or someone may have used alias email addresses to create multiple profiles on SM.