You do not need permission to use most Wikipedia pictures if they have been posted online following the Wikipedia rules. Wikipedia offers a wealth of encyclopedia type articles written and posted by users. Following the same principles, Wikimedia Commons was developed and contains freely usable files submitted by the public. Most images imbedded in Wikipedia itself can be copied also as long as a copyright restriction does not appear on the web page. The images that are copyright protected include business logos and movie posters and similar images. To copy and use copyrighted pictures you will first need to get permission from the owner of the material. You can freely copy public domain images and freely licensed images. Any derivatives of the freely licensed images must also be freely licensed.