diff --git a/database/books.go b/database/books.go
index 8229546..5ee69f0 100644
--- a/database/books.go
+++ b/database/books.go
@@ -16,28 +16,29 @@ const (
 )
 
 type Book struct {
-	Id          string
-	Title       string
-	Author      []string
-	Contributor string
-	Publisher   string
-	Description string
-	Subject     []string
-	Date        string
-	Lang        []string
-	Isbn        string
-	Type        string
-	Format      string
-	Source      string
-	Relation    string
-	Coverage    string
-	Rights      string
-	Meta        string
-	FileSize    int
-	Cover       bool
-	Active      bool
-	BadQuality  int `bad_quality`
-	Keywords    []string
+	Id                  string
+	Title               string
+	Author              []string
+	Contributor         string
+	Publisher           string
+	Description         string
+	Subject             []string
+	Date                string
+	Lang                []string
+	Isbn                string
+	Type                string
+	Format              string
+	Source              string
+	Relation            string
+	Coverage            string
+	Rights              string
+	Meta                string
+	FileSize            int
+	Cover               bool
+	Active              bool
+	BadQuality          int      `bad_quality`
+	BadQualityReporters []string `bad_quality_reporters`
+	Keywords            []string
 }
 
 func indexBooks(coll *mgo.Collection) {
@@ -132,8 +133,24 @@ func updateBook(coll *mgo.Collection, id string, data map[string]interface{}) er
 	return coll.Update(bson.M{"id": id}, bson.M{"$set": data})
 }
 
-func flagBadQuality(coll *mgo.Collection, id string) error {
-	return coll.Update(bson.M{"id": id}, bson.M{"$inc": bson.M{"bad_quality": 1}})
+func flagBadQuality(coll *mgo.Collection, id string, user string) error {
+	b, err := getBookId(coll, id)
+	if err != nil {
+		return err
+	}
+
+	for _, reporter := range b.BadQualityReporters {
+		if reporter == user {
+			return nil
+		}
+	}
+	return coll.Update(
+		bson.M{"id": id},
+		bson.M{
+			"$inc":      bson.M{"bad_quality": 1},
+			"$addToSet": bson.M{"bad_quality_reporters": user},
+		},
+	)
 }
 
 func activeBook(coll *mgo.Collection, id string) error {
diff --git a/database/books_test.go b/database/books_test.go
index 7b259cf..227a897 100644
--- a/database/books_test.go
+++ b/database/books_test.go
@@ -101,9 +101,9 @@ func TestFlag(t *testing.T) {
 	}
 	db.ActiveBook(id3)
 
-	db.FlagBadQuality(id)
-	db.FlagBadQuality(id)
-	db.FlagBadQuality(id3)
+	db.FlagBadQuality(id, "1")
+	db.FlagBadQuality(id, "2")
+	db.FlagBadQuality(id3, "1")
 
 	b, _ := db.GetBookId(id)
 	if b.BadQuality != 2 {
diff --git a/database/database.go b/database/database.go
index 172967e..75a0ae4 100644
--- a/database/database.go
+++ b/database/database.go
@@ -85,9 +85,9 @@ func (db *DB) UpdateBook(id string, data map[string]interface{}) error {
 	return updateBook(booksColl, id, data)
 }
 
-func (db *DB) FlagBadQuality(id string) error {
+func (db *DB) FlagBadQuality(id string, user string) error {
 	booksColl := db.session.DB(db.name).C(books_coll)
-	return flagBadQuality(booksColl, id)
+	return flagBadQuality(booksColl, id, user)
 }
 
 func (db *DB) ActiveBook(id string) error {
diff --git a/templates/book.html b/templates/book.html
index 71c6037..6fdaed2 100644
--- a/templates/book.html
+++ b/templates/book.html
@@ -1,6 +1,7 @@
 {{template "header.html" .S}}
 
 {{$isAdmin := .S.IsAdmin}}
+{{$flaggedBadQuality := .FlaggedBadQuality}}
 {{with .Book}}
 <script>
 function delBook(){
@@ -60,7 +61,7 @@ function delBook(){
 		{{end}}
 		<div class="pull-right">
 			<br />
-			<a href="/flag/bad_quality/{{.Id}}" class="btn btn-small"><i class="icon-warning-sign"></i> Report bad quality</a>
+			<a href="{{if $flaggedBadQuality}}#{{else}}/flag/bad_quality/{{.Id}}{{end}}" class="btn btn-small{{if $flaggedBadQuality}} disabled{{end}}"><i class="icon-warning-sign"></i> Report bad quality</a>
 		</div>
 	</div>
 	</div>
diff --git a/trantor.go b/trantor.go
index ff8af9f..0898eb6 100644
--- a/trantor.go
+++ b/trantor.go
@@ -40,9 +40,10 @@ func logoutHandler(h handler) {
 }
 
 type bookData struct {
-	S           Status
-	Book        database.Book
-	Description []string
+	S                 Status
+	Book              database.Book
+	Description       []string
+	FlaggedBadQuality bool
 }
 
 func bookHandler(h handler) {
@@ -56,6 +57,13 @@ func bookHandler(h handler) {
 	}
 	data.Book = book
 	data.Description = strings.Split(data.Book.Description, "\n")
+	data.FlaggedBadQuality = false
+	for _, reporter := range book.BadQualityReporters {
+		if reporter == h.sess.User || reporter == h.sess.Id() {
+			data.FlaggedBadQuality = true
+			break
+		}
+	}
 	loadTemplate(h, "book", data)
 }
 
@@ -90,7 +98,11 @@ func downloadHandler(h handler) {
 
 func flagHandler(h handler) {
 	id := mux.Vars(h.r)["id"]
-	err := h.db.FlagBadQuality(id)
+	user := h.sess.Id()
+	if h.sess.User != "" {
+		user = h.sess.User
+	}
+	err := h.db.FlagBadQuality(id, user)
 	if err != nil {
 		log.Warn("An error ocurred while flaging ", id, ": ", err)
 	}