The chat log can be a powerful tool when it comes to reporting people for harassment or griefing. In the future, if people do that to you, ask them to stop. If they keep doing it, explain that it's griefing, etc. If there's a chance of a language barrier, use the auto-translate thing to be like "{please stop} {Rescue}" or something. Make sure they know you don't want them doing it, and if they answer "lol no" then you have proof they know they're messing with you and won't stop, so that alone would be useful in a report.
Anyone who's smart will say absolutely nothing, ignore you, and continue to do it.

That's basically what a lot of people in the DF already do (regarding any form of suboptimal play that they are given advice on), even the people who aren't trolling.