Well, if you lose your private key and it get into their hand, as of now, yes, you can be impersonalized. As for perfect forward secrecy, it will be enabled soo

Well, if you lose your private key and it get into their hand, as of now, yes, you can be impersonalized. As for perfect forward secrecy, it will be enabled sooner or later. We currently don't handle the case where your computer itself get compromised and the disk content is made available. Those scenario should be handled by encrypting your devices and sandboxing network facing applications. In Linux, we also use DBus as the main IPC between the client and the daemon. Anyone with root access could theoretically mess with it and do a local MiM attack. There is little any application can do about this kind of compromission so it is kind of pointless to try to tackle them. At best it would slow such an attack, at worst give a false sense of security.