Pinterest (see an extract from the Pinterest Terms & Conditions at the end of this post) through the use of the Pin It bookmarking tool then you can insert a small line of HTML into the <head> section of your blog/website template to revoke access to Pinterest.
This 2-step mini-tutorial works on Blogger and Wordpress.org. Click on any image to enlarge it.
The line of code you need to insert is
<meta name="pinterest" content="nopin" />
It needs to be inserted just below the opening <head> section of your template
Navigate to your blog/website template
Find the opening <head> tag.
Place your cursor after the closing bracket and hit 'Enter' to create a new line.
Insert the meta name code from above
As you can see here, I have clicked on the "Pin It" button in my browser and the pop-up alert automatically appears. It says "This site doesn't allow pinning to Pinterest. Please contact the owner with any questions. Thanks for visiting!"
Information source: BBC News
Also, please be aware that the direct URL of your image can be used and "pinned". There will always be hacks and backdoors if someone wants to copy your content.
This "How To" originally appeared on the Typecast blog in February 2012