I know that a lot of people have an electronic lock on their phone, so no one else can use it, but my personal advice would be not to use this.
I have on average one mobile phone, each week, handed to me, when it has been found in a seat pockets or on the floor of the aircraft. If it has not got an electronic lock, I have been able to phone a family member or someone the customer has recently called and am often able to reunite the phone, sometimes in the baggage hall, especially if the customer is travelling with someone else that can be rung by the family member or me.
If the phone has a lock on it, it is impossible to reunite it or know who it belongs to, so it just gets handed in to Customer Services in the Arrival hall.
Just thought I would share that snippet of info with you.