There's nothing wrong or unprecedented about creating exceptions for particular circumstances - people acting in a specific capacity or otherwise.

For example, ambulances and firefighters are certainly also allowed to speed, when they're carrying out their duties - we've added exceptions to our laws for those circumstances, and done so as part of the normal democratic process. More mundanely, a park ranger is going to be allowed to do things like not pay the same parking fees that everyone else is allowed to, or cull animals out of season when the general population isn't allowed to hunt.

This is fine! In a democratic society, we make the laws, and within certain bounds we can make whatever we want legal or illegal. We can also debate about whether or not certain groups that represent us should have certain powers, and it's also perfectly fine to have different points of view about what exact powers they should have. But fundamentally, all that's really going on here is we're deciding to delegate certain powers and responsibilities to a particular branch of government, which of course works on our behalf.

The problem here isn't that the police have these exceptions carved out for them, the problem is that - at least arguably, there's room for debate here - the democratic process and rule of law has broken down in this instance, and the police aren't following the law at all.

Now there's always considerable shades of gray in situations like this - arguably more so in common law countries, where there's layers and layers of interpretation on top of everything, and a good deal of vagueness in quite a lot of the law. It's been generally accepted for a long time that the police have a certain amount of latitude to break various laws in ways that are not remotely spelled out in the course of investigating crimes; many would argue (with some justification) that this covers what the FBI is doing here. There's nothing inherently wrong with this argument, as long as there really are checks and balances - that is, if the interpretation of what laws police are allowed to break isn't arbitrary, but is the result of some kind of consensus where the judicial system and the legislative system (the democratic process) has set bounds as it sees fit. I personally would be in favor of generally stricter limits, less vagueness and greater scrutiny of precisely what laws the police are allowed to break and when - but still, there's nothing _inherently_ wrong with the situation we're in now, at least to the degree that police conduct does follow the rule of law and it isn't "police getting away with things just because they're police".

And on the more general subject of police and the rule of law - I don't find this particular instance with the FBI particularly problematic; I would prefer stricter limits here but I don't think this is an instance where the rule of law has broken down. I do think that the situation with entrapment in general _is_ a genuine problem - for example, the FBI has been manufacturing terrorist plots and cajoling/bribing people to help out in some small way that never would have if they didn't need the money, just because they're Muslim (which the FBI has been doing repeatedly). That, I think, is a clear example of an instance where the judicial system has clearly failed. Or even worse, the many police departments that routinely murder black people with hardly ever any real repercussions.

But again - the problem isn't with the police having exceptions to the law, the problem is with a breakdown of the rule of law.