The world's digesting the fallout of the Brussels bombing, from doing airport-like bag checks on Brussels subways to getting a crash applied chemistry course on TATP, the explosive of choice for both the Paris bombers and Tuesday's team.
The two primary ingredients of TATP are hydrogen peroxide and acetone. Both can be found with ease a hardware store or even the cosmetics section of a grocery store or drug store; the latter begs for the Britishism of a "chemist's shop" in this setting.
The resulting witches' brew (with the nom-de-guerre "Mother of Satan" in some circles) is very volatile and easy to accidentally blow up, but for folks planning on blowing themselves up for the cause anyways, a premature path to martyrdom isn't too much of a deterrent.
Rush has been joking about a "bomb show loophole" as of late. One wonders if someone might want to literally do something about that. If one put hydrogen peroxide and acetone under close watch like we've done with the Sudafed previously used as a meth precursor, one could make TATP creation a lot harder. The question there is whether the inconvenience to the bombers is more than the inconvenience to the general populous.
The CBC piece points again to the overwhelmed Belgian police and intelligence folks. While they were muddling through Walloon-Flemish divisions in their government, a rather toxic Muslim subculture was developing, helped along by folks not wanting to raise red flags for fear of being tagged as racists. That's not just a problem with Belgium, but elite pride of being the capital of Europe and trying to make a multicultural country and continent work left the downside of such efforts either outside their field of vision or unactionable due to their ideological frameworks.