Links to other sites
 

Hi everyone,
Visitors of ours often place links in posts and signatures to sites we would prefer not to link to - advertising their own products or web sites etc.
Is there a quick way to find and list, check and moderate all posts with external links that posters place, say on a daily, weekly, monthly or total forum basis?
We would still like to allow links and signatures for genuine posters offering helpful links, but would like to control / delete the others without spending hours trawling through all the posts.
Regards and thanks in advance,
Tom