Can iPad be hacked if passwords security is questionable?

Is it possible for a "family member" that knows my passwords and has had access to my iPad to control my iPad from a different location? ....Camera or even turn off my iPad completely? Recently my Ipad screen had been completely lock out with out my knowledge. The timing of this event was after an arguement with this family member. I had to take it back to store to activate it. Can the iPad be controled from a different location?