Crumbling texts and books are being digitised thanks to anti-spam tools.
To thwart spammers many websites force visitors to transcribe obscured words or characters before they get access. Now instead of random words many sites are taking text from old books and documents that have been scanned by character reading software. The words supplied are those the software cannot read but humans can, helping to complete the conversion of old texts to digital form.
Read more at http://news.bbc.co.uk/2/hi/technology/7567692.stm
