Valve announced that Steam now has a chat filter, whether players wanted it or not. In the latter case, they will be able to disable it and see all the strong language they desire.
Steam's profanity and slur filter will be on by default as the latest update introduced the feature to the platform. Long-time users of Valve's storefront and launcher may notice this change and prefer not to use it. Thankfully, Gaben's crew thought of everything it seems and let players manually turn it off in the settings.
It appears that one of the main reasons for Valve to introduce the filter to Steam was the toxicity players would pick up in online games after their tempers flared up due to the competitive nature of their matches.
Furthermore, the filter will only be enabled for the players you are not familiar with by default. Messages from friends will be fully visible unless chosen otherwise manually.
Valve noted that the functionality may be somewhat limited and the filter will not catch all the slurs and profanities that creative bad actors can come up with. For that reason, they added the ability to have custom filter lists where each individual user can create a group of words they don't want to see.
The filter will be applied in both Steam chat and all the supporting games. Therefore, when you're playing CS:GO, Dota 2 or Destiny 2, you might start seeing more obscured text than you're used to.