them on their sites (e.g. the right to use or sell the photos you post). If you do not like their terms, consider using another site or be careful what you post on the site --
you might, for instance, on a site that has undesirable terms, simply post a link to your work that is posted on a site that does allow you to retain your rights, restrict downloads, etc.
Even if the site doesn't claim rights to your works, you should state on your site or on your entries that you clearly retain rights to your works. It can be as simple as a
copyright notice or a Creative Commons
notice placed on the bottom on the webpages, or, for pictures, you can place a watermark on
the photos themselves. Such actions indicate that you do reserve your automatic rights under copyright to your works and reminds others than just because your works are posted
online doesn't mean that they can be freely used by anyone for any purpose.
A handy flowchart
has been made to help you decide which
license might be right for your desired purposes.