Point 1: Lyft's API comes with a contractual agreement regarding acceptable usage. Uber deliberately breached that agreement. This is a breach of property rights.
Point 2: They breached Lyft's property rights with the intent of stalking Lyft drivers, and of harming Lyft as an organization. This shows the breach of property rights was not neutral or positive, but rather was an activity meant to harm the property owner, and to reduce the competitive landscape.
Point 3: It was a clear violation of law. I include this last because law only loosely correlates with morality; however law draws the lines on the playing field and it is worth explicitly noting that Uber arranged for its employees to break federal law, repeatedly, for Uber's benefit.
If you don't think property rights are important, go talk with a Libertarian.