If what he says is true - that ex-Muslims don't speak up because of the higher risk of being targeted by psychopaths in Islam than in Christianity - then the problem is easily solved by using a forum which allows anonymity, like this one.
Which defeats the whole purpose doesn't it? People in this forum are in the same boat and don't have to convince each other of their apostasy. It's a kind of,pardon my expression,underground group.
Their anonymity leaves a room for reasonable doubt[for outsiders] that they were real Muslims in the first place.
They become like the unknown quantity in algebra,they could be Islam haters,Christian nuts ,etc. etc.
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The World is my country, all mankind are my brethren, and to do good is my religion.
Thomas Paine
Facts do not cease to exist because they are ignored !- Aldous Huxley