No, because if a scooter is just left lying around on the street it is abandoned property and so generally there is no law against taking it.

Which is the same problem that Bird is facing--in cities where they aren't actually permitted by the appropriate authority (city, county, etc.), Birds are abandoned property. In cities where they have been granted a permit to conduct business activities, the question is more nebulous, but thus far DAs are decisively on the side of not treating it as a crime.