Avoiding spreading false information because that's leading the community to react quickly.
And if you caught someone spreading that type of info then you have to inform him that he shouldn't do that. As you've said, he needs to validate his information first before spreading it. We know on how quick news are spreaded throughout the web.
But this is something that is really difficult to do in this market, I say this because as we know there are people that are interested to spread FUD because they want to benefit from the panic created by it, this no longer works in bitcoin but it can work in smaller communities, in fact I have seen this in action where FUD was spread and some people began selling their coins for 10% of its current value.
Even though there are people interested in generating FUD out of nothing, we still have to realize that for this space to grow, people need to understand what they are into first, as this is what would make the idea of FUD not even a thing to pay attention to in the first place.
The reason why a lot of people pay attention to FUD and tend to act so much on it by panicking is because they are ignorant of the space they are in and as long as you are ignorant, it will be very hard to even realize that some steps you are making are wrong.