How can I disable Internet access for programs running in Wine?

If you run wine as a seperate user, you can use the iptables owner module to disable internet access. For instance, if you create an user "wine", you can use the following commands:

iptables -A OUTPUT --uid-owner wine -m tcp -p tcp -j REJECT --reject-with tcp-reset #fast, but only for tcp

iptables -A OUTPUT --uid-owner wine -j REJECT #all other protocols