The statement in your quoted post is false. Just because there are several accounts using the same IP, doesn't mean all of them are going to get banned if one gets - that would only happen if we knew or found out that said accounts are connected. There are IP bans, however they don't ban all users using that IP but rather do what the following quote describes:
Q: Why is my IP banned? What are those units of evil?
A: Your IP might be banned because it was used by a user that got perma banned. Don't worry - IP bans decay over time if there's not too many of them during a small period. If you register using a banned IP, are using TOR, VPNs or well known proxies, you will have to pay a small fee. This is to prevent spammers while allowing legitimate members to post without many restrictions.
Source:
https://bitcointalk.org/index.php?topic=703657.0#post_faqP.S. This belongs in Meta, moved.