[Suggestion] Customizable content-based chat filter

I'm sure everyone is aware of the prevalence of RMT spammers in the game. I can scarcely visit the market area in any major city without having a spammer assault my chat box. Blacklisting and reporting has little effect as the spammers are constantly creating new accounts. Yet the content of their spam changes very little over time.

Another MMORPG I played years ago had an ingenious solution to the spam problem: regex-based chat filters. Players could create custom filters and any message matching them would be ignored. Being regex-based the filters could cope with minor variations in messages. Soon after the filters were implemented, someone made a filter that blocked all of the common RMT spam and started distributing it as a chat macro (in that particular game you could add links to the chat which would execute commands when clicked).

Can we please have such filter functionality here? I'm tired of blacklisting several RMT spammers per day.