This may be a stupid question, but: What do you use it for? Cannot everyone basically edit the client code and do whatever with your data? I've only used Firebase for prototyping.
[1] http://firebase.google.com/docs/database/security [2] https://events.google.com/io2016/schedule?sid=af641ff7-0bef-...
With Firebase, Vue-Fire (Firebase bindings for Vue.js), crossfilter and chart.js, you can whip up a functional and sweet analytics dashboard or [insert pet project here] in a weekend.
It gets the headache of a backend (and user auth) out of the way.
As for security - the Firebase security rules and server side authentication allow you to lock things down.
> It gets the headache of a backend (and user auth) out of the way.
You can get the same if you use other tools.
The realtime stuff is the only big thing they do most other projects don’t, and even for that there are currently several quite well working implementations out there.
A lot of eggs in one basket admittedly, but that basket looks pretty robust for now.