"Facebook, unlike Twitter, has a strict policy against multiple personal accounts and pseudonyms -- which it doesn't enforce"
Since I have pseudonymous accounts of both Facebook and Twitter, I know that neither of them enforce this rule because, apart from any ethical considerations, they can’t. If I create a Twitter account as Lord Tantamount Horseposture, who are Twitter to say that it isn’t my name (especially in the UK, where it is a freeborn Englishman’s right to call himself whatever he pleases).
Forcing women fleeing domestic violence, political dissidents and people with beliefs different from their employers’ to post under their “real” names gets us nowhere, as a moment’s thought about the topic will reveal.
"Social networks should be obliged to ban anonymous accounts. "
If anything they should be forced to ban verified accounts, since I for one couldn’t care less about what Russell Brand or any other sleb thinks about absolutely anything at all, but that’s a different point. The author has stumbled across what I labelled some time ago as the “Clinton Paradox”. I chose this name after Hilary Clinton gave a speech that I reasonably paraphrase as “we want free speech on the internet, except for people we disagree with”.