Banksy may have a positive image in the public lately, thanks to his charitable efforts toward a man who he accidentally made homeless by painting his water tank squat, but his work still packs a punch. This alleged piece by him, spotted in LA, reads "Vandals found vandalizing this vandalism will be prosecuted." It makes obvious references to the stigma of street art (to some, that it is vandalism), but also to the vandalizing and removal of his work from walls.
His Slave Labour and No Ball Games pieces were recently removed from walls in June and July to be sold at auctions, so it makes sense for Banksy to respond now. Just a week ago, a hotel in England boarded up one of his pieces to protect it from being destroyed or stolen. Two days after that, it was announced that Flower Girl would be sold at an auction house in LA, which was originally located on the wall of a Hollywood gas station (maybe Drake would be down to buy it, given his known affinity for Banksy).
Regardless of whether this is an actual Banksy or not, it does draw attention to the vast amount of lifting and vandalizing of his work, especially recently. Last December, Banksy spoke out against Stephan Keslzer, a New York-based art dealer, who showed Banksy pieces at Art Basel Miami without his permission. It just goes to show that we as a culture still have a long way to go in accepting street art's benefits and appreciating it ethically.
UPDATE: Representatives have confirmed that the street art was not done by Banksy. In an email to the New York Times, a spokesperson wrote that Banksy "has used the word ‘vandalism’ before, but the piece is fake." A street artist by the name Strömberg has taken credit for the piece and has posted in-progress pictures of the Banksy-esque piece to his Facebook page.