If you are a mouse or a 21st century American I have some advice for you: learn to identify traps, then don't take the bait.
While driving down the road, several of my sons and I were watching some 20-somethings put up Black Lives Matter yard-signs in a neighborhood around West 150th Street in Cleveland. My oldest son stated it best. "Everyone believes that black people count just as much as whites, except for racists. So when someone says to you 'Black lives matter' what they really mean to say to you is 'You're a racist.' It's just an accusation."
He's right obviously. It's the same leftist abuse of language which infects the pathetic chant of the Occupy Movement "We. Are. The Ninety-nine Percent!!" But they're not; they are a tiny sliver of the American populace. They may speak for somewhere between 5% and 15% of the victicrat population, but that's probably generous of me.
Unfortunately some people who aren't anywhere near the fringe left have taken the rhetorical bait. The group Blue Lives Matter is one which I heartily support, but Oh! how I wish they hadn't named themselves that. Once you realize that saying "Black Lives Matter" is really a challenge which could be phrased as the question, "Are you going to support us or the police?", then saying "Blue Lives Matter" can be interpret as answering "No, I don't support you; I support the Police." It is a way to inadvertently perpetuate the perception that the police are out to get anyone who is black. That perception is a win for BLM and left's booming victim industry.
The latest abuse of this comes from the Charles Sheldon-style Protestant Socialist contingent in the form of WWJD-ing the rhetoric. The first place I saw this was a Facebook placard which simply appropriated the voice of Christ saying things like "Jesus didn't say all lives matter, He said leper's lives matter. Jesus didn't say all lives matter, He said the poor's lives matter." And on and on. The truth is that Our Lord didn't speak in hashtags and soundbites at all, and that is the best counterpoint here. One could point out the many times that Jesus used universal language (ever hear of John 3:16?) but I'd be wary of taking the bait.
The other place I saw something similar was a Patheos article which I won't even link to. It actually uses the Beatitudes in an attempt to make a similar point. It has a cartoon of Christ saying "Blessed are the poor in spirit," and a listener objecting "No, Jesus! Blessed are we ALL!" So the message is that anyone who says "All lives matter" is telling Jesus to shut up. One could point out that none of the Beatitudes mention race, but again, I think that getting into a theological discussion on this is getting into pearls/swine territory and we know how that ends. It's best to stay in one piece.
So the best comeback to shouts of "Black Lives Matter!" is not "Blue lives matter" or even "All lives matter". Calling out the Black Lives Matter movement for what it is, an organization profiting from civil unrest and organized by racist agitators, is the best reaction to anything touching which smells of their caustic rhetoric. Christians and especially American Christians have to become aware of real motives and quit being so gullible. Jesus instructed us as much.