Ehhh... maybe.
Your radios are transmitting ANI and a squelch code, but the two items are independent. A 'foreigner' who ignores the CTCSS or DCS squelch code (carrier squelch) could see your ANI. Squelch codes don't make your comms private, only make it possible for you to ignore the rest of the world or access a repeater. It all depends on how the 'foreigners' are programmed. Someone wanting to ferret out your ANI's can get them.
I also recall that the Icom radios will decode 5-tone data when in a 'muted' condition, if the code meets the received mask and an "OR' condition is on the memory channel line.
Bottom line for any radio communication: if you don't want it out there don't transmit it. Someone, somewhere will figure it out.