unless you're in the server. and witness someone doing something, you shouldn't be taking action on them. if the ppl you trust so much are so trust worthy, then get them 2 get admin. if you're in the server playing, and the entire server keeps bitching about a person in particular doing something, well that's a bit diff. but 2 get told on say steam or something "oh so and so did this" then log on the server and take action = a no no. you should be joining under a false name and monitoring them, and then give them the appropriate warning/ban based on what they did.
repeat offenders will continue 2 repeat offend... so it's not like there's no reason you can't watch them and then do your job properly. I have many people that hold high credibility towards myself, but when they tell me of an issue (which seems 2 happen every 20 minutes or so lol) I jump on and monitor the person, not act blindly on there call.