Author here: I completely agree that it applies to any database and I tried to mention it in the article. The reason I wrote about MongoDB is:<p>- I wrote about it before and could compare results from my previous post<p>- It&#x27;s popular and there are a lot of public instances of it<p>- MacKeeper exposed 13 million user accounts through their public MongoDB instance<p>And I actually wrote a follow-up post on Memcached to highlight the same issue: <a href="https:&#x2F;&#x2F;blog.shodan.io&#x2F;memory-as-a-service&#x2F;" rel="nofollow">https:&#x2F;&#x2F;blog.shodan.io&#x2F;memory-as-a-service&#x2F;</a>