ok - than contact them and ask for the specific url - if it contains childporn (or pics of girls below 18) you get serious troubles (even in the us!) - if the site is legal in the us - dont worry anyway
tom
their e-mail adress is on the first page of the letter - just drop them a note.
p.s. links to "artistic nude" sites are illegal as soon as they are on sites containing links to other sexual oriented sites - wich means if you run a model link list - nude pics of a 12 year old girl can be legal - if you run a porn link list - these "artistic nude pics" are illegal
hope that helped a bit