Encrypt all the things!

Oh, and you can confirm this: sudo lshw

That shows the motherboards view of the world.

On my workstations the network section looks like this:

        *-pci:4
             description: PCI bridge
             product: 82801JI (ICH10 Family) PCI Express Root Port 5
             vendor: Intel Corporation
             physical id: 1c.4
             bus info: pci@0000:00:1c.4
             version: 00
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:89 ioport:2000(size=4096) memory:fc000000-fc0fffff ioport:df500000(size=2097152)
           *-network
                description: Ethernet interface
                product: NetXtreme BCM5764M Gigabit Ethernet PCIe
                vendor: Broadcom Corporation
                physical id: 0
                bus info: pci@0000:02:00.0
                logical name: eth0
                version: 10
                serial: 00:1f:29:06:d1:41
                size: 1Gbit/s
                capacity: 1Gbit/s
                width: 64 bits
                clock: 33MHz
                capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
                configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.134 duplex=full firmware=5764m-v3.35 ip=192.168.1.9 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
                resources: irq:100 memory:fc000000-fc00ffff

Note that the network info hangs under the PCI bridge section and that the card is allocated IRQ under resources... the workstation treats this as a physical extension of the motherboard.

On the Pi this shows like this:

  *-network:0
       description: Ethernet interface
       physical id: 1
       logical name: eth0
       serial: b8:27:eb:73:6a:f9
       size: 10Mbit/s
       capacity: 100Mbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=smsc95xx driverversion=22-Aug-2005 duplex=half firmware=smsc95xx USB 2.0 Ethernet link=no multicast=yes port=MII speed=10Mbit/s
  *-network:1
       description: Ethernet interface
       physical id: 2
       logical name: eth1
       serial: 00:80:8e:8a:92:8d
       size: 100Mbit/s
       capacity: 100Mbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=asix driverversion=22-Dec-2011 duplex=full firmware=ASIX AX88772 USB 2.0 Ethernet ip=192.168.203.115 link=yes multicast=yes port=MII speed=100Mbit/s

Note how both interfaces claim to be USB 2.0 under configuration. The Pi treats this as a proxied piece of plug and play hardware that is managed by the USB controller.