Yeah, I mean, nothing either of us said precludes the possibility of it happening, or bad actors using such technology in the future - that'll just have to be handled when the bar for such effort is sufficienctly low to increases the number of nutters willing, and able, to do it.
I suppose, in terms of science/engineering information, then its really the specific information - such as using ready-do-obtain chemicals to produce something truely dangerous to a larger population - than the actual principles or science behind it.
If someone was truely dedicated to do mass harm then they will probably find the information they need anyway (that is, they are willing to spend all their resources and not care about consequences). But limiting certain specifics will raise the bar and greatly reduce the pool of people crazy/mad enough to do it, and have the capability. So regardless of personal info, or military secrets, I do think there is some "information" which the public does not need to know, and the benefit of knowing is outweighed by the dangers of it being frelly available. These are of course all extreme cases - and the informaiton I am talking about is most likely restricted in most countries anyway.
I'm pretty sure many here are on the same page, with any disagreement being quite specific cases. Although it does seem that in certain parts of the world, what we consider benign, and useful information is censored because it conflicts with peopels beliefs (historical facts, sex education, evolution, geology etc..). I suppose that is freely available, in spite of efforts, since in the west, censorship doesn't really work all that well.