I run a free business directory. I am not able to check daily the thousands of links I added to it. The problem is that a "safe link", after years could become a "dirty link". For example, when a valued website added in my directory years back, changes ownership to become a website displaying porno or a website from where stuff harming your PC is downloadable. That could get my website -- that is linking the bad website, into the risk of being banned by search engines. Did anybody experience similar problems? Could anybody suggest me a solution? Is there a software that could detect quickly these bad links? Thanks