Is wetcanvas.com Safe?

This site requires the artist to grant irrevocable right to use of posted content. The second provision is especially troubling: "13. You grant the following licenses with respect to Content you post or submit to the web site, or otherwise make available through the WetCanvas Service. a. You hereby expressly grant to F+W a royalty-free, perpetual, non-exclusive, world-wide, irrevocable right and license to use, reproduce, adapt, modify, publish, edit, translate, perform, transmit, or otherwise distribute and display the Content on, in connection with, or to advertise, promote or archive the web site, and any future features & services for the WetCanvas community, as is necessary for the operation & preservation of WetCanvas & any future features & services for the WetCanvas community, in any form, medium or technology now known or later developed. This license is necessary to allow F+W to operate and properly host the web site, as well as develop new features and services for the WetCanvas community as new online technologies arise. It does not give F+W the right to use your Content in any way it sees fit, but merely allows F+W to include your Content on the web site, to adapt it as necessary in order to display it, and to use your Content in promoting the web site to other users & potential partners (such as in the creation of business brochures & media kits for interested parties such as the press and potential advertisers). The granting of this non-exclusive right is related to the WetCanvas service and any future features & services for the WetCanvas community in development now, or in the future. Other commercial endeavors, such as, but not limited to the publication of books, prints, magazines, DVDs, CD compilations, and non-related works require express permission from the artist or owner of the copyright to use such content in that manner. b. With respect to Content you submit to the Reference Image Library, you grant to all other users of the web site a royalty-free, perpetual, non-exclusive, world-wide, irrevocable right and license to use your uploaded images as reference images in the creation of new artwork in a different medium (such as painting, sculpture, and so on), and to sell the artwork they create pursuant to this license to use the image. You do not grant other users the right to digitally alter the image or to otherwise use or sell the image in its unaltered state. You retain the copyright to the original image."