Back when I was a youngster playing nettrek, the same thing happened. Basically, those smart enough to hack the code could create their own cheats. The wikipedia page says that game mechanics were changed so that borgs no longer had a specific advantage, but I don't know what those game mechanics were. Though it was pretty obvious if you were playing against a borg or not at least in the early days. In play chat also alerted people to those that were playing borgs.
Back in the day, you would shoot at a borg, and if your shell was aimed perfectly, it would side-step one tank width while the shell was in flight. You couldn't kill one unless you were right on top of it (or had guided missile or laser).
https://en.wikipedia.org/wiki/Netrek