diff --git a/.eslintrc.yml b/.eslintrc.yml
index 1b46da9..7363843 100644
--- a/.eslintrc.yml
+++ b/.eslintrc.yml
@@ -32,3 +32,4 @@ rules:
   semi:
     - error
     - never
+  no-debugger: warn
diff --git a/README.md b/README.md
index c64a0c7..607ade1 100644
--- a/README.md
+++ b/README.md
@@ -9,8 +9,9 @@
 - [ ] show clearly what are the directions of :knows
 - [x] show also who knows this person
 - [ ] login for different pod providers
-- [ ] faster (parallel) crawling
+- [x] faster (parallel) crawling
 - [ ] search people
 - [ ] highlight also people who know the person
 - [ ] highlight people whose button is crawled in PersonList
 - [ ] add custom starting point for crawling
+- [ ] support extended profile (seeAlso, sameAs)
diff --git a/package.json b/package.json
index aaf99c0..607cd0a 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
     "d3-selection": "^3.0.0",
     "d3-zoom": "^3.0.0",
     "eslint-plugin-react-hooks": "^4.2.0",
+    "limiter": "^2.1.0",
     "node-sass": "^6.0.1",
     "numeric": "^1.2.6",
     "rdf-namespaces": "^1.9.2",
diff --git a/src/components/PeopleList.tsx b/src/components/PeopleList.tsx
index 4b40bc9..7859ac1 100644
--- a/src/components/PeopleList.tsx
+++ b/src/components/PeopleList.tsx
@@ -7,7 +7,7 @@ interface Props {
 
 export const PeopleList = ({ people, ...props }: Props) => (
   <div {...props}>
-    <div>{Object.keys(people).length}</div>
+    <div>total: {Object.keys(people).length}</div>
     <div>
       pending:{' '}
       {
diff --git a/src/data/BFSFriends.ts b/src/data/BFSFriends.ts
index e81518a..acb1c57 100644
--- a/src/data/BFSFriends.ts
+++ b/src/data/BFSFriends.ts
@@ -8,12 +8,22 @@ import {
 } from '@inrupt/solid-client'
 import { foaf, vcard } from 'rdf-namespaces'
 import { Person } from '../components/DataContainer'
+import { RateLimiter } from 'limiter'
+
+const limiter = new RateLimiter({ tokensPerInterval: 1, interval: 50 })
+
+const limitedFetch: typeof fetch = async (...props) => {
+  await limiter.removeTokens(1)
+  return await fetch(...props)
+}
 
 export const findFriends = async (
   webId: IriString,
 ): Promise<{ name: string; friends: IriString[]; photo: string }> => {
   if (webId) {
-    const dataset = await getSolidDataset(getResourceUrl(webId), { fetch })
+    const dataset = await getSolidDataset(getResourceUrl(webId), {
+      fetch: limitedFetch,
+    })
     const person = getThing(dataset, webId)
     if (person) {
       const friends = getTermAll(person, foaf.knows).map(a => a.value)
@@ -47,56 +57,60 @@ export const BFSFriends = (
         .map(person => person.status)
         .includes('pending')
     ) {
-      // take a first unvisited person
-      const unvisitedPerson = Object.values(people).find(
+      // take all unvisited persons
+      const unvisitedPersons = Object.values(people).filter(
         person => person.status === 'pending',
       )
-      if (unvisitedPerson) {
-        // fetch their friends
-        try {
-          const { name, photo, friends } = await findFriends(
-            unvisitedPerson.uri,
-          )
-          const unvisited: Person = {
-            ...unvisitedPerson,
-            status: 'success',
-            knows: new Set(friends.map(uri => fixUri(uri))),
-            name,
-            photo,
-          }
+      if (unvisitedPersons.length > 0) {
+        await Promise.all(
+          unvisitedPersons.map(async unvisitedPerson => {
+            // fetch their friends
+            try {
+              const { name, photo, friends } = await findFriends(
+                unvisitedPerson.uri,
+              )
+              const unvisited: Person = {
+                ...unvisitedPerson,
+                status: 'success',
+                knows: new Set(friends.map(uri => fixUri(uri))),
+                name,
+                photo,
+              }
 
-          // add their friends
-          const newlyFoundFriends = Object.fromEntries(
-            friends
-              .map(
-                uri =>
-                  [
-                    fixUri(uri),
-                    {
-                      status: 'pending',
-                      knows: new Set(),
-                      name: '',
-                      uri: fixUri(uri),
-                    } as Person,
-                  ] as [IriString, Person],
+              // add their friends
+              const newlyFoundFriends = Object.fromEntries(
+                friends
+                  .map(
+                    uri =>
+                      [
+                        fixUri(uri),
+                        {
+                          status: 'pending',
+                          knows: new Set(),
+                          name: '',
+                          uri: fixUri(uri),
+                        } as Person,
+                      ] as [IriString, Person],
+                  )
+                  .filter(([uri]) => !Object.keys(people).includes(uri)),
               )
-              .filter(([uri]) => !Object.keys(people).includes(uri)),
-          )
 
-          people = {
-            ...people,
-            ...newlyFoundFriends,
-            [unvisited.uri]: unvisited,
-          }
-        } catch (e) {
-          // set their status to error
-          people = {
-            ...people,
-            [unvisitedPerson.uri]: { ...unvisitedPerson, status: 'error' },
-          }
-        } finally {
-          onChange({ ...people })
-        }
+              people = {
+                ...people,
+                ...newlyFoundFriends,
+                [unvisited.uri]: unvisited,
+              }
+            } catch (e) {
+              // set their status to error
+              people = {
+                ...people,
+                [unvisitedPerson.uri]: { ...unvisitedPerson, status: 'error' },
+              }
+            } finally {
+              onChange({ ...people })
+            }
+          }),
+        )
       } else break
     }
   })()
diff --git a/yarn.lock b/yarn.lock
index 45577f3..87ca864 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7585,6 +7585,11 @@ jsprim@^1.2.2:
     array-includes "^3.1.2"
     object.assign "^4.1.2"
 
+just-performance@4.3.0:
+  version "4.3.0"
+  resolved "https://registry.yarnpkg.com/just-performance/-/just-performance-4.3.0.tgz#cc2bc8c9227f09e97b6b1df4cd0de2df7ae16db1"
+  integrity sha512-L7RjvtJsL0QO8xFs5wEoDDzzJwoiowRw6Rn/GnvldlchS2JQr9wFYPiwZcDfrbbujEKqKN0tvENdbjXdYhDp5Q==
+
 killable@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/killable/-/killable-1.0.1.tgz#4c8ce441187a061c7474fb87ca08e2a638194892"
@@ -7665,6 +7670,13 @@ levn@~0.3.0:
     prelude-ls "~1.1.2"
     type-check "~0.3.2"
 
+limiter@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/limiter/-/limiter-2.1.0.tgz#d38d7c5b63729bb84fb0c4d8594b7e955a5182a2"
+  integrity sha512-361TYz6iay6n+9KvUUImqdLuFigK+K79qrUtBsXhJTLdH4rIt/r1y8r1iozwh8KbZNpujbFTSh74mJ7bwbAMOw==
+  dependencies:
+    just-performance "4.3.0"
+
 lines-and-columns@^1.1.6:
   version "1.1.6"
   resolved "https://registry.yarnpkg.com/lines-and-columns/-/lines-and-columns-1.1.6.tgz#1c00c743b433cd0a4e80758f7b64a57440d9ff00"