I'm just gonna keep your initial claim here for visibility

Vigilante justice is always wrong

Now, where did I claim that it's never wrong? Because that's what you seem to argue. You won't find such a claim from me though, because I agree with your implied point, which is more like "vigilante justice is usually wrong because an emotional mob doesn't weigh facts or proportional response, it just acts based on feeling". So yeah, that one seems great. But not ALWAYS wrong though.

I'll just give another example, since you gave one as well. Kid1 gets his bike stolen by kid2. He sees it happening and while he doesn't know the thief personally, he (with his parents help) contacts the police and provides a very detailed description of the bike and a decent visual description of the thief. Because this isn't really a top prio case, nothing happens for about 6 months. Then kid1 sees kid2 riding the bike around town, and he lucks into kid2 parking it in front of a small shop and going inside. Kid1 walks up to the bike, makes sure it's his, and rides off into the sunset with it.

So I ask - was it really always wrong for me to go and get my bike back?