It has the potential to be a nice plugin. But then the developers seem to have gotten all greedy. This plugin doesn't really work because weird thumbnail images display instead of your own, no matter WHAT you do to try and fix it. I haven't had the issue of it displaying outside links on this plugin.
However, when you go and get support for THIS plugin about the thumbnail issue, you're told to go get their newer and better related posts plugin.
Only problem is...THAT plugin forces you to join a service and display posts from external website. Um....no.
So this seems like a really shoddy and underhanded way of offering something for "free" on WordPress. I don't like your tactics and I don't like the way you are handling it. If I wanted to get slimed by a used car salesman, I'd go buy a used car. Instead, I'm just going to delete all of your plugins.