We believe E-Stim Connect is safe. E-Stim in general does have some minor risks, (we recommend you do not use if you are pregnant, suffer from epilepsy or a heart condition), but the use of E-Stim Connect does not increase those risks, apart from the fact you are potentially giving a complete stranger control over a device that can cause pain and uncomfortable sensations - but for some, that is the point!!
E-Stim Connect offers an external layer of secure control over your 2B via the internet. You still retain full control over your 2B at all times.
Should a remote user get a little 'frisky' and attempt to take you beyond your comfort levels then you can either setup the level blocking system (see Preferences), or manually reduce the output level, hit the OFF button, or simply disconnect the remote user.
Using E-Stim with a remote user does require an element of trust, so do not place yourself in a position where you could reach the controls of your 2B.