Rashi explains that chamas, violence, refers to robbery, which had become rampant. Indeed, as Chazal note, the decree of ultimate destruction for that generation was the result of their blatant robbery. What was “unique” about their type of robbery that distinguished it to such an extent and effected their annihilation?
The Ozhrover Rebbe z.l. explains that they derived no material benefit from the fruits of their theft. Their thievery always remained within the parameters of legitimacy, since they stole less than the value of a prutah, a coin designated as the minimum standard for theft. They stole for the specific purpose of stealing, but they were careful to stay within the boundaries of the law. Indeed, they performed every form of abominable activity, but they found a heter, permission, for their evil behavior. Every type of behavior was excused and justified. It was a generation in which the sinners performed every degenerate and repulsive act, but defined their iniquity as culture and enlightenment. Never was it viewed in its true essence. Indeed, they probably told Noach that the deluge, if it would come, would engulf only himself and not them.
This was the root of their invidious behavior and consequent annihilation. When one sins in a manner for which he can be admonished, the rebuke might be effective in motivating the sinner to repent. However, when one justifies his miscreant behavior, when one “steals less than the value of a prutah,” he indicates that he sins only for one purpose– to challenge Hashem! This is the pasuk’s interpretation, “And the earth was corrupted before Hashem.” Only “before Hashem”, Who knows what is in the recesses of everyone’s mind, is it considered corruption. Their corruption was defined by the senseless stealing, rather than the halachic limitations. It was this form of immorality that sealed their fate.
