I only use it to talk to friends overseas and I just told them I'm no longer going to use WhatsApp so we need to switch to something else. I don't think it was much of a hassle as we've switched thru almost all the popular IM apps over the years so they were fine with it, and I'm sure they still use it, just not to message me since I don't use it
But WhatsApp os encrypted, unlike Facebook (my entire office uses it for that reason, maybe all of Turkey for all I know)