CCP have clarified their position on players using multiple accounts, saying what is and isn’t allowed. You’re still allowed to run multiple subscriptions - even playing them at the same time with the help of multiboxing software - but automating actions, using Input Broadcasting & Input Multiplexing, have been banned.
Getting caught performing either within Eve can result in a permaban.
“Playing with multiple accounts at the same time has a long history within EVE Online, and has always been permitted,” CCP Falcon wrote on Eve’s forums. “There are various ways to do it, and since there’s been a lot of discussion surrounding what is and isn’t allowed, we’d like to clarify a few terms and exactly how the EULA and our Policies must be interpreted and how some things are shifting.”
Falcon began by reiterating that multiboxing - “playing as multiple separate characters, simultaneously, across a number of accounts” - is still allowed. Players use multiboxing to do everything from scouting ahead in PvP to gang boosting. It’s also the cornerstone of spying in Eve, having a dummy account active in one corporation, while your real account is active in another.
He also clarified that input automation, which was banned outright in March, 2013 is still very much banned. IA is when you’ve a bot controlling your account performing actions for you, players used them to run mining operations and time consuming ore refining patterns.
The change is that input broadcasting and input multiplexing, which refers to multiplying inputs across multiple instances of Eve will also result in a ban. From 1 January, 2015 the first occurrence of IB or IM will result in a 30 day ban, the second will see a permanent ban. This action won’t be taken retrospectively so you’ve till 31 December to get it out of your system.
There are some allowed IB and IM actions, Falcon says. “Actions taken that do not have an impact on the EVE universe and are carried out for convenience,” such as “altering EVE Online client settings, Window positions and arrangements (of the EVE Online client in your operating system’s desktop environment), and The login process” are all ok.
If you aren’t sure whether your use case is allowed of not then you should contact CCP.