Session: Physical Location in Fediverse data model

Topics ActivityStreams Data model Fediverse Fediverse Extension Proposal Location

Convener: Mike Waggoner (@herebox@onewhilshire.la)

Participants who chose to record their names here:

Manton (@manton@manton.org)
Bob Wyman (@bobwyman@mastodon.social)

Notes

Summary

Existing Activity Stream 2 (AS2) Vocabularies
- Object - location property
  - https://www.w3.org/TR/activitystreams-vocabulary/#dfn-location
- Object - Type - Place
  - https://www.w3.org/TR/activitystreams-vocabulary/#places
- Object - Type - Activity
- Fediverse apps with location support
  - https://gath.io - Events
- Schema.org - Place (including geo-shape)
  - Maybe too much / kitchen sink
Next steps
- Try pushing data using existing Activity Streams 2 (AS2) fields to Fediverse ( e.g. Mastodon )
- Fediverse Enhancement Proposals (FEPs)
  - Propose an extension to protocol or data model
  - https://codeberg.org/fediverse/fep/
- Write / extend Fediverse app that uses the existing AS2 data model
  - e.g. Add to Firefish?

Agenda Topics / Discussion Ideas

Privacy
- People are often surprised / cautious to share location
- Risk to safety if location is shared by default or unintentionally
- Option to opt-in
- Photo metadata - e.g. filtering exif
- Backlash from users / Risk
- Privacy context might change after some amount of time ( e.g. public check-ins after some delay )
- Approximate location as a part of ActivityPub semantics (radius field)
Use Cases
- Dots ( e.g. Foursquare / Swarm )
- Lines / Paths / Stream of GPS Coords ( e.g. Strava )
- Sets of Un-Connected Dots ( e.g. Public Art in a region )
- Areas / Geofencing ( e.g. Geoloqi )
- Presence
- Events ( e.g. gath.io )
- Followed who are in a similar location
- Followers, Strangers, Lists
- Sending messages to a geofenced area
- Approximate location sharing
- Private tracking with delayed public location sharing
Existing Efforts
- AS2 - Activity Vocabulary - Location - GPS coordinates on the Location object
  - https://www.w3.org/TR/activitystreams-vocabulary/#dfn-location
  - Location exists for any object
    - long & lon + altitude
- Place object that is used as the location object in the ActivityStreams2 (AS2) specification
  - Mastodon doesn’t support Place objects.
  - Whole section, 5.3 Representing Places https://www.w3.org/TR/activitystreams-vocabulary/#places
    - radius
- Mastodon Issues from 2016-2018
  - https://github.com/mastodon/mastodon/issues/8340 - GPS Location in Toots (not linked to images)
  - https://github.com/mastodon/mastodon/issues/281#issuecomment-1321138657 - GeoTag toggle for post (Enhancement)
- No known “first-class” Fediverse project where location is the primary data focus
  - Similar use-cases (Events gath.io)
Implementation Ideas
- Extend open source
- Ingest existing commercial
- Add interface to include location data in a post ( e.g. to Mastodon )
  - We are unsure what the result of sending location data into existing services will be (e.g. will Mastodon display it ??)
- Automate reading metadata from posts ( e.g. exif data, links to mapping service )
- Location Data Store
  - Commercial stores ( Foursquare, Google, Facebook )
  - Open Street Map
  - Reverse geo-coding
    - e.g. https://github.com/tomayac
- Data Models
  - AS2 - Place
  - Indiweb - hCard / vcard
    - https://microformats.org/wiki/hcard
  - Schema.org - Place
    - https://schema.org/Place
- Meridian - Project based on OpenStreetMap data to make easier API to build apps on
  - https://latl.ong/
  - Generally - Need more tools to push new locations back to the existing databases
- Stream of GPS Coords
  - Example of storing a path over time - icecondor.com/b/
- Draft Fediverse Enhancement Proposal (FEP) to extend ActivityStreams Place object with additional fields
  - https://codeberg.org/fediverse/fep
  - Consider pointing to Schema.org Place?
  - Narrow profile of just the basic fields most people need