quite possibly this change of policy was just a slick marketing gimmick by enterprising Car2Go execs with price of dozens of stolen cars factored in - certainly its publicity just got a big bump up
The article includes a graph of "Vehicle thefts in U.S. cities where Car2Go operates* in 2018" and Chicago is at the top of the list. If that was their pilot city, interesting choice. Alternatively, if they rolled out the policy change in all locations at the same time, interesting choice.
Article doesn't report problems in other cities...