If the hackers gained access to the database, then they would be able to do whatever they want. The character data, account data and the notices/news/events on the maple story website are all in that database; they would do a lot more, and would hack better accounts.
Also, for databases, there is a neat feature that lets you only allow a connection from certain ip. You cannot change your ip to their ip because you need a unique ip to connect to the internet, technically.
Ok, so you think a lot of people are getting hacked, right? No, at the time that I made this thread, there were 34637 people online in global maple story. On max, you will only play for 5 hours a day at most, and over two 5 hour periods, it is reasonable to say that the number of players online would be steady, meaning around 70000 people play maple story. If you say that around 300 people got hacked so far, that is a 0.5% chance of you being hacked. I took into account the minimum people that play, not everyone plays every day. The 0.5% would be the minimum, I estimate to around 0.01% of the total population of 2009 to be hacked.
I am a computer programmer, I know my stuff. Please feel free to ask questions and I will provide the answers I know. The program I used to get the number of people online is legit, it acts as a client connecting to the server, sending the same packets, the server sends the amount of people online, I am fairly sure.
I have some theories about how you would be able to hack an account, but if Wizet has coded login properly, I see no possible way. Hacker, come get me, I dare you.