Unfortunately it's not at all uncommon for college students, usually young men, to engage in dumb stunts or pranks that get themselves or others killed. Of course it wasn't smart for Otto Warmbier to decide to swipe a propaganda poster in North Korea, of all places. That offence, which likely would have earned a wrist slap in a civilized country, got him murdered in North Korea. His death, after being returned brain dead from North Korea, provoked a flurry of hysteria from certain right wing sites, alleging that liberals celebrated his punishment and murder.
Exhibit A was a Larry Wilmore nightly show in which Warmbier was lambasted for his folly. I looked at it, and it was the most tasteless and nasty thing I've seen from Wilmore, even granting that it was done long before anybody knew Warmbier would die for his offence. To imply that this was some common liberal propaganda effort strikes me as ridiculous though, even if Wilmore happens to be a liberal comic. Wilmore's offence was cruelty and tastelessness, not liberalism. In any case, Wilmore and his show are gone.
Similarly, the idiot adjunct professor who got fired for saying that Warmbier got what he deserved was guilty of being an asshole, not a liberal.
Yes, there are liberal assholes (not to mention conservatives of the same inclination), but it's ridiculous to indict a whole group for the offences of a few jerks.