It sounds like you have the Image Protection feature in your account preferences on, so when you look at the full size images, you encounter that message when you attempt to download them back to your system. All you need do is change the setting in the Image Management area of your Account Preferences (which you can reach from the My Account menu) to disable this feature while you are downloading your images. You can then re-enable the feature when you have finished.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .