[EugeneOZ]

Never send DB output directly to frontend, send object, filled by only necessary values from DB output. Otherwise you'll meet security issues and these "_" prefixes will be smalles part of your problems.

[Kiro]

And how are you supposed to do that using Mongolab, MongoHQ or Firebase?

[knewter]

you seem to be taking as a given that those are acceptable things to do.

[lowboy]

And you seem to be implying that they're not okay to do. Feel free to substantiate your opinion.

[eknkc]

I do that. It's not about sending them directly. It's the underlying field name. I just keep _id fields as _id fields when I prepare data for output.