David Gerard wrote:
http://wwmm.ch.cam.ac.uk/blogs/murrayrust/?p=997
They have a specific hate-on for Wikipedia:
"Chemical Abstracts Service (CAS) objects to anyone encouraging the use of SciFinder - and STN - to curate third-party databases or chemical substance collections, including the one found in Wikipedia."
Here's the situation in a nutshell, for those who don't have time to read the referenced blog entry (though it's an informative read).
There's an obvious need in chemistry for a short, easy-to-use, unique identifier for every chemical compound in use. You might think that the chemical formulas you learned in high school -- H20 for water, NaCl for salt, H2SO4 for sulfuric acid, etc. -- would suffice for this, but that system rapidly breaks down for larger molecules, both because it's increasingly cumbersome, and harder and harder to guarantee uniqueness when there are multiple distinct structures containing the same number of C's, H's, N's, and O's. Also there's a need for unique numbers for substances such as gasoline which are mixtures of different molecules and which therefore don't have single chemical formulas.
The good news is that there is a widely-used set of numbers providing the desired attributes: short, easy-to-use, unique. These are "CAS numbers", and they're a de-facto standard. Water is 7732-18-5, salt is 7647-14-5, sulfuric acid is 7664-93-9, gasoline is 86290-81-5. As I understand it, in published work on chemistry, everyone routinely uses CAS numbers to clarify the identities of the chemicals they're writing about; I believe journals tend to require this. The creation of the CAS database was obviously a huge undertaking, and CAS deserves rewards for the huge amount of work that has gone into it.
The problem, of course, is that CAS is trying to guarantee their rewards by forcing everyone who uses their numbers to pay various fees. Their need to underwrite their work (even though they're a non-profit) stands in direct opposition to humanity's need for these numbers to be free and open. The details are different, but in broad outlines the story is a sadly familiar one, well-known to any student of free and open information.