Is Multi-Logging Detectable???

Hey, I often multilog on to two accounts at once, I usually just open up firefox with swift switch and click loggin very quickly on both so they log in together. However, can Jagex see that two accounts are coming from the same computer and ban me?

Is there a 100% safe way to do it?

oh and also, does anyone know a good way to not log out while fishing, cause when i multilog i often fish or wc on one acc while i train on the other, and sometimes i get too busy watching the training guy and the other one logs out

 

It is detectable.