Good point about spam filters.
The word "attack" was used. "Spreading FUD" is not the same as having legitimate critique. But I'm actually doing the opposite of FUD-- I'm saying that Bitcoin is not threatened, and people reading this do not need to be afraid or doubtful.
Yes there have been attacks and vulnerabilities in the past, but in this case the "attack" is making Bitcoin stronger by paying for transactions, and if it creates a secondary market dependent on Bitcoin, then it also increases the value of the Bitcoin network. It is a foot shot for the attackers, except that they make money off it.
I admit, I may be wrong. Maybe this is devastating and without dramatic intervention Bitcoin will crumble.