More recently Springer realized that even books out of copyright could generate new revenue and offered authors the "benefit" of keeping their books in print indefinitely by voluntarily extending copyright to infinity. Actually, you can get nearly all math books free online at the rogue Russian "Genesis Library", with websites libgen.in and gen.lib.rec.ec (most of my books are there -- help yourself). Which is better: lunch money royalties once a year or wider free distribution of your books? (Emphasis added)
Yes, that is a senior mathematician telling people "go to Library Genesis and download my books for free".
More telling is the history of mathematics publishing and relatively recent, and unfortunately unsuccessful, efforts in establishing the World Mathematics Library.
Here is Mumford on the issue of money:
Of course, I hear loud cries of "who pays?". Yes, it's not free. But moving to something like the above would free up large amounts of library money currently being spent for overpriced journals, e.g. Springer and Elsevier (maybe even shaming NYU into reducing its ridiculous price for Communications in Pure and Applied Math). The cost of running an online journal is certainly fairly small, though by no means zero. There are no printing, mailing and storage costs and no subscription record keeping. Refereeing is done for nothing, manuscripts are prepared by the author in latex with fixed formatting packages so they are ready to post, editing beyond a spell check is a luxury we can omit, esp. in our multi-lingual world where the niceties of grammar are increasingly forgotten or never learned by foreign speakers.
The image below is a personal letter of thanks to Springer, the man, from mathematicians (Hilbert! Caratheodory! Courant! Bieberbach! Hecke! Landau! etc) thanking him for his efforts and sacrifices to keep two important journals going. This would never happen today. Mumford is in the league of the signatories, and he is giving modern publishing corporations what for.
(Ignore the date of posting---1st April---it's a serious article)