Hi @blue_puma,
Welcome to the MongoDB Community and thank you for the feedback!
Flags are a combination of user-submitted flags as well as system heuristics. Unusual activity from a brand new user (for example, posting a high velocity of topics or links to a new site) will be flagged for review by our team of site moderators.
The notification you received is rare, but is triggered by posting too many links to a new site in a short period of time (which is a very typical spammer activity). The wording in this notification hasn’t been customised from the default yet, but I’ll add a follow-up action for us to improve the messaging.
Speed bumps for low trust level users allow the community time to catch up on your questions and give new users some time to learn more about the community (which will also increase your trust level and privileges). We have been relaxing some checks as the community grows and can self-moderate more effectively, but the starting point has been to err in favour of not allowing spammers easy access to annoy our community.
Unfortunately we have continuous attempts from spammers, and there is an ongoing game of adjusting technical measures to get the right balance of spam detection. We’re trying to minimise the need for traffic light CAPTCHAs and other more extreme measures that frustrate our real audience.
When moderators review flags, we consider false detection and adjust settings appropriately. This includes possibility of adding domains to our allow or reject lists and considering adjusting other activity thresholds. Since you are the first new user to post so many links to the MongoDB Playground in a short period of time, we had not added the site to an allow list yet – but I did so when handling your flagged posts.
As you spend more time contributing positively in the forums, you will earn higher trust levels and have fewer speed bumps. The next level (Sprout) can be earned in as little as 10 minutes and removes the cap on posts & replies. Congrats @blue_puma – you’ve already earned that trust level 
.
Regards,
Stennie