How do you confuse mob vengeance (Tarring and Feathering) with Terrorism? Go back and read the first paragraph of the first search result you linked to. A mob cannot by definition is not a group engage in organized pre-planned behavior. No more terrorism than a couple bullies impulsively beating up another kid at school for making them angry.
...Unless your definition of "Terrorism" is "anything that scares people", which would encompass all violence and all threats of violence between people. Although there are differences of opinion on the details, there is a consensus as defining Terrorism as a type of asymmetric warfare, itself a subset of warfare, which is then a subset of violence. Your posts seem to indicate you think "Terrorism" is any type of violence.
Non-combatants targeting non-combatants alone show your examples don't understand what "Terrorism" is.