"We welcome responses from any interested party."
Which suggests the El Reg readership might have a chance to influence this area.
Keep them focused and skip the jokes.
There are a lot of issues that should be considered.
Remember the usual excuse data fetishists trot out is there is no other way to find these people.
But point out what that "Doomsday" scenario means.
A person who has no history of radical beliefs
A person who is not radicallized by viewing any known web site/FB page/YT channel/Twitter feed
A person who needs to make no purchases to carry out their plan
A person who makes no contact with any known offender (or potential offender) to carry it out.
So when I explain it in calm, non hysterical tones, does this sound plausible to you? Or does it sound like complete bu***hit?