We have no way of knowing whether or not they are legal.
The postings I have seen online have all been by churches and religious orders, who are all non-profit, are not using the book for profit, and may have received permission to post it.
I suppose you could e-mail them and ask if they have posted it legally, but unless you are the copyright owner for the book, it’s not your business.
If it bothers you, buy a copy and then you have fulfilled your duty under the law.
I myself bought both a hardcopy and a Kindle version of the latest Manual, so I’m covered.
