This sucks hoping I haven't lost anything when I get back on the game going check FC chest to make sure as well.
On a side note though we can't really blame SE for this speaking as a programmer if you know how to hack and break lines of codes it is fairly easy to back door into a program and modify it to your needs. I'm guessing all the RMTs would really need to get a hold of is your online ID your ISP details and then use what ever program they made to spam buy a certain item on the market boards using the packets that the game send and receives to the client.
Nothing is ever secure once you know the algorithms used even if they used something like SHA-256 to encrypt data it may end up pointless as this type of encryption is now easily crackable if you know what your doing.