I can't speak about all of the posters on LAT but regarding two of the psuedoanonnymous ones who occasionally visit Zenpundit:

Nadezhda: A very bright, well educated lady. Would seem to have some real background on policy issues. Has another blog Chez Nadezhda

praktike: currently studying Arabic in Cairo and is less active now than formerly. Smart and an effective debater who does not lose his cool. Surfs the net daily with a professional discipline and thoroughness that I find very impressive. Appears connected to liberal organizations in the real world. Guest blogged on high profile sites. Positions on issues are usually "liberal hawk" variety. Going out on a limb, I'd say he is foreign born or son of immigrants to U.S. or Britain.

Always worth the time to read their stuff even if you disagree.