It should not be forgotten that ordinary citizens who are willing to testify against criminals are in a similar situation as LEOs who testify.
Yet those same ordinary citizens wouldn't be allowed to protect themselves in many (most?) jurisdictions.
This leads to thoughtful citizens being unwilling to turn in the bad guys which leads to general destruction of law and order.
This is not a new problem. It was notable in the 1920's in Chicago and NY when the word "gangster" was invented. And wasn't it Chicago that popularized the driveby shooting????