Google's Messages app is a clean and simple way to text, making customization but making up for it with simplicity and web messaging support. The latest addition to the app is spam protection, though it comes with some caveats.
This seems to be a server side rollout as most devices aren't getting this option yet. However, those who are getting a pop up at the bottom of the app offer the feature and allow you to turn it off.
Why would you turn it off? Spam protection can't be a bad thing, can it? Because it does require Google to collect data from you. Message contents are safe, but data about the messages themselves will be collected and sent to Google for this feature to work.
If you're all about privacy, you'll want to turn this feature off. You can do this from the pop-up or by heading to Settings> Advanced> Spam protection. For the rest of us, if SMS is an issue, this should help quite a bit. The feature should be rolling out to everyone so keep an eye out!
Source: Android Police