Depends on your definition of secure - last I heard, default BBM was still using a globally shared key and logging your messages; BB has on several occasions ha

Depends on your definition of secure - last I heard, default BBM was still using a globally shared key and logging your messages; BB has on several occasions handed messages over to governments at request (such as during London riots etc). BBM is only secure in combination with a self-hosted BES server (and on which you have installed your own CA certs).