I understand what you're trying to say. However, this is not technically correct, and people who are not technically inclined may believe this to be correct.
The truth is that you can use the same computer across many different networks, or even on the same network with a refreshed dynamic IP address, and such a table wouldn't allow the cross referencing you're suggesting.
For a username -> ip address table to provide this functionality, the users would need to access the site from the same IP address, not the same computer.
It's worth noting that the table would become polluted by things like public wifi, shared home internet, VPNs, etc. as well
The truth is that you can use the same computer across many different networks, or even on the same network with a refreshed dynamic IP address, and such a table wouldn't allow the cross referencing you're suggesting.
For a username -> ip address table to provide this functionality, the users would need to access the site from the same IP address, not the same computer.
It's worth noting that the table would become polluted by things like public wifi, shared home internet, VPNs, etc. as well