Photographers are often worried that images displayed on a website will be stolen and used elsewhere without their permission. Indeed, this will happen. But what they take is not that valuable and could be good for you.
You will find that professional photographer websites gladly display their images because they want you to see their work. Are they worried you will steal the images they display. Not really. What is displayed is a low resolution image, meaning it has enough pixels for a good display on a web page but not enough to make a decent print.
There is no way to prevent website users from copying what is displayed on the screen. Even if you cannot use a "Save As" button, you can always do a screen capture using the "Print Scr" button. Nothing displayed is safe.
The low resolution images on a website are of little value and most professionals are happy to promote their work by displaying their images. Check out what you can see from famous photographers like Art Wolfe (ArtWolfe.com). While you can make it a bit harder for a person to use these low resolution images, it is impossible to prevent it.
The Visual Pursuits websites provide some additional protections anyway. All images uploaded get a copyright tag embedded into the image file if one is not already present. This copyright notice is normally overlaid on all images when they are displayed at sizes larger than 540x400 pixels, except when judging or if watermarks are suppressed by you or your organization.
Individual members can prevent their images from being displayed entirely or from bring displayed to non-members. This is done in the My Account menu item. If you have been selling your images for thousands of dollars you may want to choose this option.
You could decide to only let only members view your competition results but this deprives your members the opportunity of sharing their work with the public and friends.
Software Pursuits encourages you to share your work and stop worrying. Why do we make these images if not to share them?