Author here - we put up the logos for companies where members of the company use Pragli. We note in our terms of service that we reserve the right to do this, but we are happy to remove any logos of companies who request not to be used as such.
Interesting approach. Usually logo use is negotiated at purchase time. I'd be interested to see whether you suffer any consequences for playing fast and loose with logos. Might be a profitable way to break the rules like Uber, Facebook, etc.