The laws of the country hosting the site are the only laws that matter, and as far as I know, mardux is a US company. Hence, US copyright applies and it's illegal to use photos that do not belong to you.

Besides, even if there were no law against copyright infringement, you know very well it's unethical to use someone's photos in for sexual pleasure without his or her consent. (It's also not very fucking smart of you - all it does is make people more reluctant to post photos online.)