[Be Aware] EU and Country Laws: Open Free WiFi makes you liable.
This is not to be considered legal advice but to make you aware; In EU countries a court case (Sony v McFadden 2016) means that having a free open WiFi makes you liable.
It decided the operator of a wireless network can be required to protect the network with a password in order to deter users from infringing the rights of copyright holders. The Court further decided that the right holder can claim from network operators the costs related to an injunction (e.g. to prevent future infringements). They could ask you to pay the cost of the legal advice and the costs incurred by their legal team to send you a correspondence.
At the country level, each one is different. For example;
UK: If you provide non-compliant Public WI-Fi and a customer suffers loss, then you would have major problems defending a civil suit and your insurance would not cover any damages awarded against you. Non-compliant in this case falls under what is reasonable [e.g. using WEP would likely not be].
The UK list goes on: A potential GDPR breach if not managed properly. Digital Economy Act 2010 is designed reduce online copyright infringement such as illegal downloading and illegal file sharing. Anti-Terrorism, Crime and Security Act 2001, you need to be able to identify who is using your WiFi network.
What I find interesting is that Meraki might have potentially opened themselves up for liability. By providing the option to block peer-2-peer, you as a service provider or end-user trust that will do its job. If you are then found in breach of that, then you could pause your "pay out" until you take Meraki to court over failure to update the mechanism in wish you trusted (under a breach of trust).
Germany: the main one is the doctrine of Störerhaftung,aform of indirect liability for the actions of others.
Please get legal advice if you are unsure.
Personally, I would pay a third party to manage it or just not do it at all. What are your thoughts?