I was flabbergasted to see that all along, when I thought it was safe to send PDF files to clients with Password protection to stop printing, changes and image extraction - well, it is not. That security feature may as well be removed from Acrobat as it is worthless. The question remains, how do you showcase your work safely now?
The only way I can see immediately, is to open the PDF as a low res image in Photoshop. It will not look so good when the client views it, but they can't do too much with a fuzzy pixel based image.
Has Adobe acknowledged this huge hole in security? Anyone?
Did you read the warning you get when you set the password security?
Password protection for restrictions on what you can do with a PDF is an old technology which made sense when Adobe Reader/Acrobat were the only game in town. These days you do not even need an app to circumvent this "protection". You can open PDF, take pictures of the screen and then OCR them getting a pretty functional PDF with no restrictions.