I am running a general discussions forum where people can talk about anything like entertainment, sports, funny jokes, images...etc

Since it is not about "Webmasters" so the people who come and join the forum will be mostly non-webmasters, means they will not have their own websites. So should I allow links in the signature to attract webmasters too or not?

It does not have any strict rules on postings, people can post just anything... even "Thanks for sharing" kinda posts are also allowed.. do you think if this kind of posts are allowed then webmasters can join the forum and to get maximum sig links they will spam the forum with "Thanks for sharing" posts?