Comment by blueblob

I don't think this is the place that you would send your criminal plans and ideas, I think that it is a place where you can discuss things that might be embarrassing or get more objective opinions. There is still the potential problem that one of your contacts has no other contacts and can therefore guess pretty accurately whether it is you or not. There is also quite a bit of research on de-anonymizing social networks that might make this less private than some might think.