When World Kitchen took over the Pyrex brand, it started making more products out of prestressed soda-lime glass instead of borosilicate. With pre-stressed, or tempered, glass, the surface is under compression from forces inside the glass. It is stronger than borosilicate glass, but when it’s heated, it still expands as much as ordinary glass does. It doesn’t shatter immediately, because the expansion first acts only to release some of the built-in stress. But only up to a point.
One unfortunate use of Pyrex is cooking crack cocaine, which involves a container of water undergoing a rapid temperature change when the drug is converted from powder form. That process creates more stress than soda-lime glass can withstand, so an entire underground industry was forced to switch from measuring cups purchased at Walmart to test tubes and beakers stolen from labs.
The video in the link has some slo-mo goodness, and explains that there are two categories of pyrex: consumer-grade and lab-grade. So the labware theft is not of vintage materials no longer available, possibly it occurs in order to avoid being tracked by actually purchasing it; there are fewer suppliers of lab-grade apparati than there are department stores selling the cheap stuff.
Taking this idea to the illogical extreme is Texas (surprise!), where it is illegal to buy/sell an Erlenmeyer flask (among other labware) without the proper paperwork, as it is considered an aid to making illegal chemicals. (I happen to own one, along with some beakers — they comprised my bar glassware back in the days when I had housemates and we threw parties; I could mix some pretty precise cocktails, and a 600 ml beaker is a good size for such drinks. The Erlenmeyer flask’s role was that of a wine decanter.) I wonder if this is a “shall-issue” permit. Regardless, it appears easier to get a handgun in Texas than lab glassware. Or Sudafed, since Pseudoephedrine is on the list as well, without mention of a threshold below which it’s not necessary to get a permit. I’d love to hear if anyone in the Lone Star State has applied to buy (or better yet, transfers/furnishes to someone else) a cold-remedy pill.