I would like to look at the scope of Lifnei 'Iver -- the commandment to not put a stumbling block before the blind (Lev. 19:14). Specifically, I would like to know how one is punished for the sin -- does someone who causes another person to sin liable for that sin as if he did it himself? Must the violator of Lifnei 'Iver have intended that a person sinned as a result of his suggestions? And would a person be in violation of Lifnei 'Iver if he was causing somone to sin without being warned that his actions constituted the sin of Lifnei 'Iver for which he could be punished under Jewish law (e.g. restitution, fines, lashes, etc.)? Is that answer different if the person is an expert in Jewish law? If the words that sent the events in motion constituted loshon hara (gossip) or motzei shem ra (slanderous lies), does the speaker have any liability for the damage caused to the ones whom he influenced with his words?
To give these questions context, lets use a very possible hypothetical. Rabbi tells his students that smart phones are a sin and no one should have one, and that it would be best for the world if all were destroyed. Student 1 sees that his roommate owns a smart phone and destroys it on his own, thinking that this is what his rabbi would want. Did the rabbi unintentionally violate Lifnei 'Iver? To what extent is the rabbi liable for his student's theft and destruction of his roommate's property?
Second hypothetical: Rabbi tells congregation that Ploni-al-moni is an "evil man" and should be "taught a lesson." Congregant hearing this takes it upon himself to beat up Ploni-al-moni and put him in the hospital. Might the rabbi be liable for Lifnei 'Iver because he didn't also tell his congregants that he meant G-d should punish the sinner, and not them?