What' s the Noble Cause Corruption??

Answer 1

It is the theory that the worst (read, most damaging) forms of corruption result from those who believe they are acting out of some Noble Cause.

It's the "ends justify the means" argument. If the Cause [ends] is Noble, then any means should be allowed to pursue it.

The problem with that mindset, when applied to government or law enforcement, is that it corrupts those whose job it is to uphold and enforce the laws, because it leads them to believe (incorrectly) that it is acceptable to break the laws in pursuit of that noble goal.