Hm, I take issue with that.
You say that you won't take into account warnings past a certain point, but I frankly don't think that's psychologically possible. If you really want the warnings to expire, they should expire. And that process should be transparent for the users as well--we should be able to know that we don't have the Sword of Damocles hanging over our head forever, coloring the mods' perceptions of us on an unconscious level.
Basically, I see absolutely zero benefit to doing it this way other than record keeping, and frankly if you want to keep records on users dating back two, five, ten years... well, I gotta question your intent there.
This is an internet forum for a children's card game. There shouldn't be a permanent record of illegal activity on here. That's completely ridiculous.
refer to this post
My point is, once it happens, it's happened. Everyone remembers. If there's no official record of it, in some people's minds, it might be worse (i.e. a mod knows they have warned you more than once. It was twice. The mod thinks it was 5 times. Without a record, in the view of the mod, it was 5 times, not the actual result, which was twice).
I don't believe the activity is illegal - just against the board rules.
Yeah - 10 years from now, who cares...but, this site is still pretty young.
Again, I'm of the opinion that more information is better. Plus, if the mod staff can show a reduction in warnings/issues, while showing an increase in the overall population, that shows they are doing a good job, and the community is responding well to how they are dealing with issues.