Yes, it can. What the mod was reference is the use of VPNs. Even so, a person who uses VPNs telegraphs the fact because their log ons are always using a different IP. It's not proof of a sock, but it also does not disprove it's a sock. It's an unknown.
Example; my IP is pretty constant since I post from home on my laptop. It changed a couple weeks ago when I switched internet servers, but was consistent before and remains consistent after. If I had a secondary account, it would show up as the same IP. A person who uses a VPN is constantly changing. Harder to prove if they have socks, but it leaves the door open.
IT/techie people are free to chime in with their thoughts.