Vandalism detection

Main article: Vandalism

Vandalism is intentionally ignoring the consensus norms of the OpenStreetMap community about editing data. Simple mistakes and editing errors are not vandalism but may need to be reverted using some of the same tools that are used for vandalism.

Detection

Resources available now

See Feeds (map editing), Monitoring Tools and QA tools in general.

Online Services

• Find Suspicious OpenStreetMap Changesets (by number of objects created/modified/deleted, new contributers), see announcement
• new contributors feed - Personal feed of new contributers in an area. For covered areas see public BBoxs Last x days layers.
• OSMCha.org (osmcha.mapbox.com) instance of OSMCha - The OSM Changeset Analyzer: Analyze and review changesets, suspicious changes are flagged.
• OSM Latest Changes - A web application that helps to check recent OSM changes within a certain cartographic boundary.

Tools

• detect_osm_weirdness.py - An OSM "weirdness" detector: Reads minutely/hourly diffs and looks for oddly-shaped ways or ways that don't quite make sense.
• osm-weirdness - a tool to find weird changesets
• OSMCha - Python package to detect suspicious OSM changesets
• OSM Hall Monitor - Suite of Python tools: reads diff files looking for large edits, skewed ratios of deletions to total edits or modifications to total edits, or changesets with modifications across the map; also can watch specific users or objects, with notification available; smart geospatial comparison coming soon (objects of certain shapes, etc.).
• OpenStreetMap Analytic Difference Engine.

Possible other resources

• Overpass API Augmented Diffs
• osc files
• osm files with different creation date
• database

Possible libraries/algorithms to use

• Support vector machine (source)
  • LIBSVM -- A Library for Support Vector Machines
  • Support Vector Machines In PHP
• osm-stream-process - A simple Python script to make it easier to parse the minutely diff stream and perform tasks in near realtime.
• OSM Stream - Minutely clientside OpenStreetMap changeset streams; JavaScript, based on Augmented Diffs
• osm-watch - Advanced watching of OpenStreetMap changes (offline); Java, based on Augmented Diffs
• OSM Analytic Difference Engine, Diary entry - analytic live (web) service with text-based summary and visual-diff; Python, based on minutely diffs and main API
• planet-stream - streaming Augmented Diffs + Changeset metadata (minutely changesets); JavaScript; An OSM firehose - What's trending on OSM?
• Gabbar - Guarding OpenStreetMap from harmful edits using machine learning
• osm-changeset-classification - OpenStreetMap Changeset Classifier For Detecting SPAM, Imports, Reverts, and Mapping Errors

Criteria

Important: none of the below criteria alone means anything. But combined it may be worth a look...

• new user
• user name changes versus id
• number of edits
• number of changesets
• area of changesets
• lots of special actions like

• renaming
• reclassification

• edits spread over a wide area
• lots of deletions
• movement of data over a long distance
• high version numbers of objects (edit war)
• operating times (bots?)
• waylength above threshold
• way node reduction
• number of unique/similar changeset names

Reports

A periodically generated report could list possible

• changesets
• users
• areas

to be inspected closer. It could even introduce a scoring system.

Survey

• I'm dreaming of a tool that could warn you by email of any change made on a object you modified in the past which has defined properties.

• having the word "survey" in the note tag
• having a note, or a fixme, or a source tag
• in a zone of interest
• deleted object
• moved object
• ...

Research

• Neis, P.; Goetz, M.; Zipf, A. Towards Automatic Vandalism Detection in OpenStreetMap. ISPRS Int. J. Geo-Inf. 2012, 1, 315-332.
• Nitasha Singla, Sukhjit Singh Sehra, Jaiteg Singh, A Review on Vandalism Detection in OpenStreetMap Data and Emerging Trends, American Journal of Networks and Communications. Vol. 3, No. 6, 2014, pp. 77-83. doi: 10.11648/j.ajnc.20140306.12
• Smart VGI Platforms: Methods for Automatic Vandalism Detection - Confirmation Seminar, Alireza Kashian - 13 March 2014
• Andrea Ballatore. "Defacing the Map: Cartographic Vandalism in the Digital Commons." The Cartographic Journal 2014; 51(3), 214-224. DOI: 10.1179/1743277414Y.0000000085
• Vandalism in Volunteered Geographic Information revisited - GIScience News Blog, Jan 2015
• Quy Thy Truong, Guillaume Touya, Cyril De Runz. OSMWatchman: Learning How to Detect Vandalized Contributions in OSM Using a Random Forest Classifier, ISPRS International Journal of Geo-Information, MDPI, 2020, 9 (9), pp.504. doi: 10.3390/ijgi9090504

Examples

Examples of vandalism and mapping accidents:

• List_of_Vandalism_Changesets
• user blocks
• An open database of inconsistent edits observed on OSM from OSMCha
• German forum: Beispiele für Mapping-Unfälle und Vandalismus gesucht (Searching for examples of mapping accidents and vandalism)
• Editor issue leads to unexperienced users tagging underlying landuse instead of POI (examples in comments)
• How Afghan Amateur Mappers Unintentionally Punked Apple (using old OSM data)
• Somehow a urinating Android ended up in Google Maps
• Help fight advertising (Talk-us) - SEO Spam discussion + example list
• New York vandalism: changeset, statements: OSMF, Mapbox, in the press: New York Times, BBC, TechCrunch

Discussions

• Google Summer of Code (Mar, 2012)
• Detecting unwanted edits and vandalism (Apr, 2012)
• GSoC - Anomaly Detection Engine (May, 2012)
• Interesting cases of vandalism? (Feb, 2013)