diff --git a/backend/src/middleware/filterBubble/replaceParams.js b/backend/src/middleware/filterBubble/replaceParams.js
index a0ced7b15..82d39d024 100644
--- a/backend/src/middleware/filterBubble/replaceParams.js
+++ b/backend/src/middleware/filterBubble/replaceParams.js
@@ -1,7 +1,13 @@
+import { UserInputError } from 'apollo-server'
+
 export default async function replaceParams(args, context) {
   const { author = 'all' } = args.filterBubble || {}
+  const { user } = context
 
   if (author === 'followed') {
+    if (!user)
+      throw new UserInputError("You are unauthenticated - I don't know your followed users")
+
     const session = context.driver.session()
     let { records } = await session.run(
       'MATCH(followed:User)<-[:FOLLOWS]-(u {id: $userId}) RETURN followed.id',
diff --git a/backend/src/middleware/filterBubble/replaceParams.spec.js b/backend/src/middleware/filterBubble/replaceParams.spec.js
index 927a362cd..cd9e0a3da 100644
--- a/backend/src/middleware/filterBubble/replaceParams.spec.js
+++ b/backend/src/middleware/filterBubble/replaceParams.spec.js
@@ -15,7 +15,6 @@ describe('replaceParams', () => {
       records: [{ get: () => 1 }, { get: () => 2 }, { get: () => 3 }],
     })
     context = {
-      user: { id: 'u4711' },
       driver: {
         session: () => {
           return {
@@ -27,28 +26,6 @@ describe('replaceParams', () => {
     }
   })
 
-  describe('given any additional filter args', () => {
-    describe('merges', () => {
-      it('empty filter object', async () => {
-        args = { filter: {}, filterBubble: { author: 'followed' } }
-        const expected = { filter: { author: { id_in: [1, 2, 3] } } }
-        await expect(action()).resolves.toEqual(expected)
-      })
-
-      it('filter.title', async () => {
-        args = { filter: { title: 'bla' }, filterBubble: { author: 'followed' } }
-        const expected = { filter: { title: 'bla', author: { id_in: [1, 2, 3] } } }
-        await expect(action()).resolves.toEqual(expected)
-      })
-
-      it('filter.author', async () => {
-        args = { filter: { author: { name: 'bla' } }, filterBubble: { author: 'followed' } }
-        const expected = { filter: { author: { name: 'bla', id_in: [1, 2, 3] } } }
-        await expect(action()).resolves.toEqual(expected)
-      })
-    })
-  })
-
   describe('args == ', () => {
     describe('{}', () => {
       it('does not crash', async () => {
@@ -56,43 +33,96 @@ describe('replaceParams', () => {
       })
     })
 
-    describe('{ filterBubble: { author: followed } }', () => {
+    describe('unauthenticated user', () => {
       beforeEach(() => {
-        args = { filterBubble: { author: 'followed' } }
+        context.user = null
       })
 
-      it('returns args object with resolved ids of followed users', async () => {
-        const expected = { filter: { author: { id_in: [1, 2, 3] } } }
-        await expect(action()).resolves.toEqual(expected)
+      describe('{ filterBubble: { author: followed } }', () => {
+        it('throws error', async () => {
+          args = { filterBubble: { author: 'followed' } }
+          await expect(action()).rejects.toThrow('You are unauthenticated')
+        })
       })
 
-      it('makes database calls', async () => {
-        await action()
-        expect(run).toHaveBeenCalled()
+      describe('{ filterBubble: { author: all } }', () => {
+        it('removes filterBubble param', async () => {
+          const expected = {}
+          await expect(action()).resolves.toEqual(expected)
+        })
+
+        it('does not make database calls', async () => {
+          await action()
+          expect(run).not.toHaveBeenCalled()
+        })
       })
     })
 
-    describe('{ filterBubble: { } }', () => {
-      it('removes filterBubble param', async () => {
-        const expected = {}
-        await expect(action()).resolves.toEqual(expected)
+    describe('authenticated user', () => {
+      beforeEach(() => {
+        context.user = { id: 'u4711' }
       })
 
-      it('does not make database calls', async () => {
-        await action()
-        expect(run).not.toHaveBeenCalled()
-      })
-    })
+      describe('{ filterBubble: { author: followed } }', () => {
+        beforeEach(() => {
+          args = { filterBubble: { author: 'followed' } }
+        })
 
-    describe('{ filterBubble: { author: all } }', () => {
-      it('removes filterBubble param', async () => {
-        const expected = {}
-        await expect(action()).resolves.toEqual(expected)
+        it('returns args object with resolved ids of followed users', async () => {
+          const expected = { filter: { author: { id_in: [1, 2, 3] } } }
+          await expect(action()).resolves.toEqual(expected)
+        })
+
+        it('makes database calls', async () => {
+          await action()
+          expect(run).toHaveBeenCalled()
+        })
+
+        describe('given any additional filter args', () => {
+          describe('merges', () => {
+            it('empty filter object', async () => {
+              args.filter = {}
+              const expected = { filter: { author: { id_in: [1, 2, 3] } } }
+              await expect(action()).resolves.toEqual(expected)
+            })
+
+            it('filter.title', async () => {
+              args.filter = { title: 'bla' }
+              const expected = { filter: { title: 'bla', author: { id_in: [1, 2, 3] } } }
+              await expect(action()).resolves.toEqual(expected)
+            })
+
+            it('filter.author', async () => {
+              args.filter = { author: { name: 'bla' } }
+              const expected = { filter: { author: { name: 'bla', id_in: [1, 2, 3] } } }
+              await expect(action()).resolves.toEqual(expected)
+            })
+          })
+        })
       })
 
-      it('does not make database calls', async () => {
-        await action()
-        expect(run).not.toHaveBeenCalled()
+      describe('{ filterBubble: { } }', () => {
+        it('removes filterBubble param', async () => {
+          const expected = {}
+          await expect(action()).resolves.toEqual(expected)
+        })
+
+        it('does not make database calls', async () => {
+          await action()
+          expect(run).not.toHaveBeenCalled()
+        })
+      })
+
+      describe('{ filterBubble: { author: all } }', () => {
+        it('removes filterBubble param', async () => {
+          const expected = {}
+          await expect(action()).resolves.toEqual(expected)
+        })
+
+        it('does not make database calls', async () => {
+          await action()
+          expect(run).not.toHaveBeenCalled()
+        })
       })
     })
   })