diff --git a/samples/go/photo-index/main.go b/samples/go/photo-index/main.go
index 2506d55a6d..84311de75d 100644
--- a/samples/go/photo-index/main.go
+++ b/samples/go/photo-index/main.go
@@ -79,11 +79,13 @@ func index() (win bool) {
 	d.CheckErrorNoUsage(err)
 
 	byDate := types.NewGraphBuilder(db, types.MapKind, true)
-	byTag := types.NewGraphBuilder(db, types.MapKind, true)
 	byFace := types.NewGraphBuilder(db, types.MapKind, true)
+	bySource := types.NewGraphBuilder(db, types.MapKind, true)
+	byTag := types.NewGraphBuilder(db, types.MapKind, true)
 
-	tagCounts := map[types.String]int{}
 	faceCounts := map[types.String]int{}
+	sourceCounts := map[types.String]int{}
+	tagCounts := map[types.String]int{}
 	countsMtx := sync.Mutex{}
 
 	addToIndex := func(p Photo, cv types.Value) {
@@ -127,6 +129,17 @@ func index() (win bool) {
 			}
 		}
 
+		// Index by source, then date
+		moreSources := map[types.String]int{}
+		var ws struct {
+			Sources []string
+		}
+		if err = marshal.Unmarshal(cv, &ws); err == nil {
+			for _, s := range ws.Sources {
+				bySource.SetInsert([]types.Value{types.String(s), types.Number(d)}, cv)
+			}
+		}
+
 		countsMtx.Lock()
 		for tag, count := range moreTags {
 			tagCounts[tag] += count
@@ -134,6 +147,9 @@ func index() (win bool) {
 		for face, count := range moreFaces {
 			faceCounts[face] += count
 		}
+		for source, count := range moreSources {
+			sourceCounts[source] += count
+		}
 		countsMtx.Unlock()
 	}
 
@@ -171,11 +187,13 @@ func index() (win bool) {
 	}
 
 	outDS, err = db.Commit(outDS, types.NewStruct("", types.StructData{
-		"byDate":       byDate.Build(),
-		"byTag":        byTag.Build(),
-		"byFace":       byFace.Build(),
-		"tagsByCount":  stringsByCount(db, tagCounts),
-		"facesByCount": stringsByCount(db, faceCounts),
+		"byDate":         byDate.Build(),
+		"byFace":         byFace.Build(),
+		"bySource":       bySource.Build(),
+		"byTag":          byTag.Build(),
+		"facesByCount":   stringsByCount(db, faceCounts),
+		"sourcesByCount": stringsByCount(db, sourceCounts),
+		"tagsByCount":    stringsByCount(db, tagCounts),
 	}), datas.CommitOptions{
 		Meta: types.NewStruct("", types.StructData{
 			"date": types.String(time.Now().Format(time.RFC3339)),
diff --git a/samples/js/dropbox/find-photos/src/main.js b/samples/js/dropbox/find-photos/src/main.js
index fef9278b30..fab1d3bef6 100644
--- a/samples/js/dropbox/find-photos/src/main.js
+++ b/samples/js/dropbox/find-photos/src/main.js
@@ -25,12 +25,16 @@ const args = argv
   .usage(
     'Indexes Photo objects out of slurped Dropbox metadata.\n' +
     'See dropbox/slurp for how to get an access token.\n\n' +
-    'Usage: node . --access-token=<token> <in-object> <out-dataset>')
+    'Usage: node . [flags] <in-object> <out-dataset>')
   .option('access-token', {
     describe: 'Dropbox oauth access token',
     type: 'string',
     demand: true,
   })
+  .option('source-tags', {
+    describe: 'comma-separated list of source tags to write into created photos',
+    type: 'string',
+  })
   .demand(2)
   .argv;
 
@@ -82,6 +86,7 @@ async function main(): Promise<void> {
   if (!input) {
     throw `Input spec ${args._[0]} does not exist`;
   }
+  const sourceTags = new Set(args['source-tags'] ? args['source-tags'].split(',') : []);
   const outSpec = DatasetSpec.parse(args._[1]);
   const [outDB, output] = outSpec.dataset();
   let result = Promise.resolve(new Set());
@@ -92,12 +97,13 @@ async function main(): Promise<void> {
       const resources = getResources(v);
       const photo: Object = {
         id: `https://github.com/attic-labs/noms/samples/js/dropbox/find-photos#${v.id}`,
-        title: v.name,
-        tags: new Set(),
-        sizes: await getSizes(resources),
-        resources: resources,
         dateTaken: newDate(v.media_info.metadata.time_taken),
         dateUpdated: newDate(v.server_modified),
+        resources: resources,
+        sizes: await getSizes(resources),
+        sources: sourceTags,
+        tags: new Set(),
+        title: v.name,
       };
 
       if (isSubtype(hasLocation, getTypeOfValue(v.media_info.metadata))) {
diff --git a/samples/js/fb/find-photos/src/main.js b/samples/js/fb/find-photos/src/main.js
index 3a57035111..b0ba009410 100644
--- a/samples/js/fb/find-photos/src/main.js
+++ b/samples/js/fb/find-photos/src/main.js
@@ -26,6 +26,10 @@ const args = argv
     'Finds photos in slurped Facebook metadata\n\n' +
     'Usage: node . <in-path> <out-dataset>')
   .demand(2)
+  .option('source-tags', {
+    describe: 'comma-separated list of source tags to write into created photos',
+    type: 'string',
+  })
   .argv;
 
 main().catch(ex => {
@@ -82,6 +86,7 @@ async function main(): Promise<void> {
   if (!input) {
     throw `Invalid input spec: ${inSpec.toString()}`;
   }
+  const sourceTags = new Set(args['source-tags'] ? args['source-tags'].split(',') : []);
   const outSpec = DatasetSpec.parse(args._[1]);
   const [outDB, output] = outSpec.dataset();
   let result = Promise.resolve(new Set());
@@ -91,12 +96,13 @@ async function main(): Promise<void> {
     if (v instanceof Struct && isSubtype(photoType, v.type)) {
       const photo: Object = {
         id: `https://github.com/attic-labs/noms/samples/js/fb/find-photos#${v.id}`,
-        title: v.name || '',
-        sizes: await getSizes(v),
-        resources: await getResources(v),
-        tags: new Set(),  // fb has 'tags', but they are actually people not textual tags
         datePublished: new NomsDate({nsSinceEpoch: v.created_time * 1e9}),
         dateUpdated: new NomsDate({nsSinceEpoch: v.updated_time * 1e9}),
+        resources: await getResources(v),
+        sizes: await getSizes(v),
+        sources: sourceTags,
+        tags: new Set(),  // fb has 'tags', but they are actually people not textual tags
+        title: v.name || '',
       };
       if (isSubtype(placeType, v.type)) {
         photo.geoposition = getGeo(v);
diff --git a/samples/js/flickr/find-photos/src/main.js b/samples/js/flickr/find-photos/src/main.js
index 8475baaa87..13c79fbfcc 100644
--- a/samples/js/flickr/find-photos/src/main.js
+++ b/samples/js/flickr/find-photos/src/main.js
@@ -26,6 +26,10 @@ const args = argv
     'Indexes Photo objects out of slurped Flickr metadata\n\n' +
     'Usage: node . <in-object> <out-dataset>')
   .demand(2)
+  .option('source-tags', {
+    describe: 'comma-separated list of source tags to write into created photos',
+    type: 'string',
+  })
   .argv;
 
 const sizes = ['t', 's', 'm', 'l', 'o'];
@@ -88,6 +92,8 @@ async function main(): Promise<void> {
   if (!input) {
     throw `Input spec ${args._[0]} does not exist`;
   }
+
+  const sourceTags = new Set(args['source-tags'] ? args['source-tags'].split(',') : []);
   const outSpec = DatasetSpec.parse(args._[1]);
   const [outDB, output] = outSpec.dataset();
   let result = Promise.resolve(new Set());
@@ -97,12 +103,13 @@ async function main(): Promise<void> {
     if (isSubtype(imageType, getTypeOfValue(v))) {
       const photo: Object = {
         id: `https://github.com/attic-labs/noms/samples/js/flickr/find-photos#${v.id}`,
-        title: v.title,
-        tags: new Set(v.tags ? v.tags.split(' ') : []),
-        sizes: getSizes(v),
-        resources: getResources(v),
         datePublished: newDate(Number(v.dateupload) * nsInSecond),
         dateUpdated: newDate(Number(v.lastupdate) * nsInSecond),
+        resources: getResources(v),
+        sizes: getSizes(v),
+        sources: sourceTags,
+        tags: new Set(v.tags ? v.tags.split(' ') : []),
+        title: v.title,
       };
 
       if (!v.datetakenunknown) {
diff --git a/samples/js/picasa/find-photos/src/main.js b/samples/js/picasa/find-photos/src/main.js
index fdbaf7239d..a6bb9cb433 100644
--- a/samples/js/picasa/find-photos/src/main.js
+++ b/samples/js/picasa/find-photos/src/main.js
@@ -25,8 +25,12 @@ import {
 const args = argv
   .usage(
     'Finds Noms Photo objects from output of picasa/slurp\n\n' +
-    'Usage: node . <in-path> <out-dataset>')
+    'Usage: node . [flags] <in-path> <out-dataset>')
   .demand(2)
+  .option('source-tags', {
+    describe: 'comma-separated list of source tags to write into created photos',
+    type: 'string',
+  })
   .argv;
 
 main().catch(ex => {
@@ -92,10 +96,13 @@ async function main(): Promise<void> {
   if (!pinnedSpec) {
     throw `Invalid input dataset: ${inSpec.path.dataset}`;
   }
+
   const [db, input] = await pinnedSpec.value();
   if (!input) {
     throw `Invalid input spec: ${inSpec.toString()}`;
   }
+
+  const sourceTags = new Set(args['source-tags'] ? args['source-tags'].split(',') : []);
   const outSpec = DatasetSpec.parse(args._[1]);
   const [outDB, output] = outSpec.dataset();
   const result = [];
@@ -109,10 +116,11 @@ async function main(): Promise<void> {
       const photo: Object = {
         id: 'https://github.com/attic-labs/noms/samples/js/picasa/find-photos' +
             `#${v.gphotoQ24id.Q24t}`,
-        sizes: await getSizes(resources),
-        resources: resources,
         datePublished: getDate(Date.parse(v.published.Q24t)),
         dateUpdated: getDate(Date.parse(v.updated.Q24t)),
+        resources: resources,
+        sizes: await getSizes(resources),
+        sources: sourceTags,
       };
 
       if (isSubtype(hasTitle, v.type)) {