Ofcom in the UK recycle all old mobile phone numbers but the time limit needs to be increased.  Any new number could be still active in old users contacts and their numbers and messages can be seen and potentially be exposed to explicit /illegal messages.

there has been a case of a child receiving explicit pics on her new phone but luckily parents intercepted , this is not acceptable and needs to change urgently 

we need to prevent this as it can happen with any new sim card.