[somepig]

some ISPs will happily assign public IPs to any hardware address that sends a DHCP request. This means while the network segments are bridged, all local devices are potentially obtaining public IP addresses and are exposed to the internet at large.

This is problematic if you have home network devices with vulnerabilities or services running on hosts with the assumption that the host will only ever be on a private network (unauthenticated file servers, etc)

There is also an issue with the number of devices exposed to the ISP -- many will issue an address to the first device they see on a link, then ignore all other devices until the lease expires or is released. That means your PS4 may get a lease before the espressobin's Linux takes over, and the ISP will ignore the subsequent dhcp request from the espressobin.