I've never seen any content violating this rule on Reddit because criminals intent on committing gang violence (ideologues, gangsters etc.) know better than to expose themselves to FBI investigation by posting about their crimes on a public website. I have however seen about 10000 instances of content being taken down because it is a 'Call to Violence' because it says something like 'Kikes should burn', 'Jews deserve to die', etc. But honestly, they do deserve to die.