When you find a suspicious edit, try to be part of the solution, rather than merely a reporting system. :-)
If you are experienced enough, attempt to determine which account introduced the suspicious data. Contact that account through the user mail system. Presume good faith; they may well be a new and enthusiastic mapper with an incomplete understanding of OpenStreetMap. They might also be more experienced than you are and be making some form of advanced edit with which you are unfamiliar. Your goal is to make contact with the mapper in question, and find out what they intended with their edit. Ideally, either they will learn something and become a better mapper, or you will. :-)
If you aren't experienced enough to do this on your own, contact a more-experienced mapper who you trust for their judgement and ask for their assistance. Follow along so that you can proceed with less help next time.
If you aren't able to get a satisfactory response within a reasonable time, say a week or two, consider asking other mappers for their opinion on the edits. Are they really a problem, or simply rare or idiosyncratic? Consider as a group if the data should stay or not. Please note that a "satisfactory response" is not restricted to another mapper agreeing with you. :-)
Repair or revert data that is incorrect. Get help from a more-experienced mapper if you haven't done this before.
All of this should happen before you consider reaching out to the Data Working Group. The DWG and the OpenStreetMap sysadmins, do have additional tools for dealing with spammers, vandals and persistent, umm, "whackos". But these tools are rather heavy and blunt instruments. The DWG wield these tools with exquisite finesse and with surgical precision but you can help a great deal by solving
problems before they require intervention from DWG. Reserve the DWG for those things that you can not reasonably do for yourself.
You can make the initial contact and do the basic research. Please do.
Take responsibility for improving the map (we all do), but also take responsibility for improving the mappers. Temper this by understanding that the mapper who you improve may well be yourself.
And that's just fine, too. :-)
This article is based on an email to the talk-us@ mailing list on 18 November 2013.