Originally Posted by
Twinki
They might. Using the Tiered Bot Detection theory (Jagex uses a detection system split up in tiers, for example Tier 1 is low-level bot detection running 100% of the time on all players that flags possible botters, Tier 2 is further analytics on the account that's been flagged by Tier 1, then finally Tier 3 is decision/punishment) It'd make sense for Jagex to flag IP's that've been either flagged or banned by Tier 3, to further prevent, or quickly detect future goldfarming/botting.
So it might work like this:
You start goldfarming, you're running 10 accounts. One day, all your accounts are banned. Tier 3 recognizes these 10 accounts were on the same IP, and they were all banned for Goldfarming/Macroing Major. Tier 3 then adds that IP to a 'Flagged IP' Database
While Tier 1 is running, it checks that accounts IP to see if it's in the list of the Flagged IP Database, if it is, it immediately passes that account to Tier 2 for further analyzing, and the cycle continues. It's much cheaper, easier, and faster to flag previous botted IP's, and toss that it in, in the Tier 1 detection process. Remember, Tier 1 only flags accounts to be further investigated. Tier 3 is what makes the decision, and it only gets passed onto Tier 3 if Tier 2 passes it on.
Of course, this is all speculation. Jagex are the only ones who knows how it works. So frankly, you won't be getting a straight answer unless you can contact a JMod Directly.
Best practice? Get your IP changed. Ask your ISP for a new one, say you're getting DDoSed. I wouldn't recommend a VPN, since pretty much every IP a VPN could possibly hand out is most likely flagged already.