I had it a few years back but had to get it taken out as I had a VERY bad habit of playing with it. (I am like a kid at Xmas with new things to 'play' with).
My sister had one and when she went to appt to get it taken out they said they couldn't find it and she had to be referred to hospital. Never actually heard if she has it out yet or no.
Several people I know have them with no problem at all.