And of course, you can lose everything you worked for if the server runs into a problem or shuts down without notice.
This gives me heavy lulz. I am reminded of the guy that spent 2000 USD on a set of gear including a perfect 1h sword and a 22 att shield, bought locks for them, and then a glich occured causing the ITEMS to expire. I don't remember the exact thread, but he was on the Nexon forums about it.