I wouldn't say it was there exactly for a reason like this, I would just say they assumed the "intent" was there, even though it is worded poorly. Pretty easy fix, and still could be interpreted by a judge that it is illegal. Regardless of the outcome, they should really tighten it up.
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Because you keep equating the word vigilante with somehow stripping them of protection from laws. This article summarizes a lot about how I feel this will go.