Its called multiboxing, and the publisher call it not hacking or cheating. Its allowed. go and google for "swtor multiboxing" and you will be surprised, what fun it makes, when 1 guy allone, forms a group out of his own chars and clear a comlete operation area, boss included.
They multiboxer's are a growing group of nerds with lots of money. They need to have a up to date hardware, or better. Lots of them pay for more than 4 accounts. This is the resaon, why the publisher look away - multiboxer are good customers.
Sure it would not be fair, if a boxer group would kill you instantly in open pvp - but they are not interested in such things.