Are there a security and usablity problems with having to maintain an ever growing list of TLDs? Browsers need to know what the TLD in a URL is so that they kno

Are there a security and usablity problems with having to maintain an ever growing list of TLDs? Browsers need to know what the TLD in a URL is so that they know how to stop cross site cookies being created, as well as for lots of other reasons that affect useability[1]. If the TLD list gets too long could it slow down web browsers? 1. http://publicsuffix.org/learn/ http://publicsuffix.org/learn/