Unfortunately, much of the internet industry has an established history of doing just that. This heavy-handed approach to vulnerability disclosure has led to an atmosphere of distrust and is bad for everyone. Facebook's policy is intended to alleviate much of the tension involved with vulnerability disclosure.

If you're curious, the EFF has published a number of great articles on the topic:

https://www.eff.org/issues/coders/vulnerability-reporting-fa...

https://www.eff.org/deeplinks/2010/12/knowledge-power-facebo...