I believe it's a bit different. It could be different for shared computers, but, I think, for porn browsing on one's own hardware, incognito mode is more about

I believe it's a bit different. It could be different for shared computers, but, I think, for porn browsing on one's own hardware, incognito mode is more about having a separate (ephemeral) browser profile, so you aren't accidentally sharing your kinks on Facebook and Google won't (visibly, at least) associate it with your main browsing profile and won't show you relevant ads there. A comparable feature for the IM world would be "alter ego"/pseudonymous mode, where your contacts aren't provided with your identity information (google account/phone numbers/etc - not even your "normal" name or nickname), but a throw-away identities, yet you still have a convenience of using a single app. Not really private in a sense your favorite TLA won't know you, but good enough in a sense your peers won't know you. I don't think any IM system does that, without setting up separate accounts. I mean, "self-destructing" messages weren't there in a lot of systems, and users perfectly know how to delete SMS or emails they don't want to keep - and saving the ones they do. Not to say "message expiration" is a myth (haven't they learned it with Snapchat already?) Maybe that's just my view of things, though.