This addon blocks URLs sent in game chat of Garry's Mod servers. This addon is server side.
This addon is based on my bad-word-slur-blocker addon, but modified with pattern matching to block any URL or IP address sent in game chat. Both addons can be used at the same time.
Pattern matching code: https://stackoverflow.com/questions/23590304/finding-a-url-in-a-string-lua-pattern