I know, but again, unless someone sets it that way, that's not the default of browsers.
I have been using security software for ebooks for years (since 2002), but each one of them is TERRIBLE. I've been through 3 companies & either the clients have HUGE problems opening the files either b/c the clients are computer illiterate despite my clear instructions, or there are bugs in the software, or their tech support is terrible.
This last company Secure ebook (www.secure-ebook.com) just ruined my relationship with 3 clients. They claim they get back to you within 48 hours, but they never did. I had to call & leave messages at least 5 times & then e-mailed about 5-10 more. They responded back & did nothing. I sent tons of screenshots & error messages & they are clueless.
I lost tons of money trying to get my website coder to go onto one client's computer to try & open the files & it wouldn't. He also tried on his computer & I tried on mine & we both couldn't open the files. I finally had to give them insecure files which I NEVER do. It was either that or lose him. So no, don't recommend doing that. It's not an option for my proprietary material & I don't sell enough to put a ton of work into drip feeding them the material. They need it all at once.
At this point I will be suing Secure ebook, as they are totally ignoring me & they even admitted in one email that they had issues, but refused to explain when it would be fixed. I just e-mailed the owner & the Vice President on Friday.
Since this seems to be a recurring issue with every company I've purchased from & the other solutions are just TOO expensive, or they don't have the features I need, I have to find another solution, as this makes ME look bad. The only reason a client will have a less than perfect experience with me is b/c of these terrible companies.
So, the only other alternative we came up with is to make each PDF into an html page & then get a membership software program & do what we mentioned above so they can't pass out the login to others.