not illegal as in "against the law" but against the Terms of Service or use.
http://starwarsgalaxies.station.sony.com/en_US/players/content.vm?page=Policies Eula&resource=tos
2. To play the Game, you must: (i) purchase the Software (as defined below in Paragraph 7) for Star Wars Galaxies: An Empire Divided and any expansion packs you wish to play ; (ii) have a fully paid Account;
7. You acknowledge that you are bound by the terms and conditions of the Software License and Limited Warranty that accompanies the Game. You acknowledge and agree that you have not and will not acquire or obtain any intellectual property or other rights, including any right of exploitation, of any kind in or to the software, artwork, music, and other components included in the accompanying CD-ROM or DVD-ROM (the " Software ") or the Game, including, without limitation, in any character(s), item(s), credit(s) or other material or property. You may not use any third party software to modify the Software or to change game play.
You may not create, facilitate, host, link to or provide any other means through which the Game may be played by others, such as through server emulators; additionally, you may not engage in matchmaking for multi-player play over unauthorized networks. You may not decrypt or modify any data transmitted between client and server; you may not use or distribute macros or other programs which would allow unattended game play or which otherwise impact game play. You may not take any action which imposes an unreasonable or disproportionately large load (as determined by us) on our infrastructure. You may not buy, sell or auction (or host or facilitate the ability to allow others to buy, sell or auction) any Account or any Game characters, items, credits or copyrighted material or any other intellectual property owned or controlled by us or our licensors without first obtaining our express written permission .
I haven't seen one MMO that allows this.