A lot of trolling here, I've never had any issues of missing data. When claiming a db (as big and popular as mongodb) doesn't work, you should include references, company, examples on how to reproduce, etc. Enough said: http://www.mongodb.org/display/DOCS/Production+Deployments

Just as you claim that people who have had problems are trolling, so could be said about your own claim. These people are basing their opinion on their own (negative) experience, while you are doing the same based on your own (positive) experience. How is that any different?

This thread includes numerous examples of people who did indeed have grave issues with Mongo. They're not any less valid that your own example (or the ones you link to). In these topics there's always going to be positive and negative takes, but calling people trolls because - again, like you -they voice their opinion is harsh.

Are the two really equal? Given two independent sources that you don't really know: a) I've never lost data with MongoDB, b) It wiped my database

Doesn't (b) have a certain burden of proof? Maybe he had a bug in his code? Maybe he did something weird with his server? Maybe he didn't follow upgrade directions properly? Maybe he got hacked? Is it really too much to ask for something verifiable? Steps to reproduce? Log files? Assuming that the person isn't just malicious, even a before and after of db.xx.count()?