diff --git a/src/actions/signup.ts b/src/actions/signup.ts
index 11e7711..e10d812 100644
--- a/src/actions/signup.ts
+++ b/src/actions/signup.ts
@@ -62,17 +62,6 @@ export const signup = {
         }
       }
 
-      // check if user is blocked
-      if (uuid) {
-        const blockedUser = await db.getBlockedUserByUuid({ uuid: uuid });
-        if (blockedUser) {
-          throw new ActionError({
-            code: 'FORBIDDEN',
-            message: 'Du bist für die Registrierung gesperrt'
-          });
-        }
-      }
-
       await db.transaction(async (tx) => {
         const user = await tx.addUser({
           firstname: input.firstname,
diff --git a/src/app/admin/blockedUsers/BlockedUsers.svelte b/src/app/admin/blockedUsers/BlockedUsers.svelte
index dcd1429..31c7d2d 100644
--- a/src/app/admin/blockedUsers/BlockedUsers.svelte
+++ b/src/app/admin/blockedUsers/BlockedUsers.svelte
@@ -22,7 +22,7 @@
   function onBlockedUserDelete(blockedUser: BlockedUser) {
     $confirmPopupState = {
       title: 'Nutzer entblockieren?',
-      message: 'Soll der Nutzer wirklich entblockiert werden?\nDieser kann sich danach wieder registrieren.',
+      message: 'Soll der Nutzer wirklich entblockiert werden?\nDieser kann danach dem Server wieder beitreten.',
       onConfirm: () => deleteBlockedUser(blockedUser)
     };
   }
diff --git a/src/app/admin/blockedUsers/SidebarActions.svelte b/src/app/admin/blockedUsers/SidebarActions.svelte
index ae0d471..0c4fe3d 100644
--- a/src/app/admin/blockedUsers/SidebarActions.svelte
+++ b/src/app/admin/blockedUsers/SidebarActions.svelte
@@ -24,7 +24,7 @@
     submitButtonTitle: 'Erstellen',
     confirmPopupTitle: 'Nutzer blockieren',
     confirmPopupMessage:
-      'Bist du sicher, dass der Nutzer blockiert werden soll?\nEin blockierter Nutzer kann sich nicht mehr registrieren.'
+      'Bist du sicher, dass der Nutzer blockiert werden soll?\nEin blockierter Nutzer kann dem Server nicht mehr beitreten.'
   }}
   target={null}
   keys={[
diff --git a/src/app/admin/users/Users.svelte b/src/app/admin/users/Users.svelte
index 239618c..fd373b3 100644
--- a/src/app/admin/users/Users.svelte
+++ b/src/app/admin/users/Users.svelte
@@ -1,6 +1,6 @@
 <script lang="ts">
   import DataTable from '@components/admin/table/DataTable.svelte';
-  import { deleteUser, editUser, type User, users } from '@app/admin/users/users.ts';
+  import { blockUser, deleteUser, editUser, type User, users } from '@app/admin/users/users.ts';
   import CrudPopup from '@components/admin/popup/CrudPopup.svelte';
   import { confirmPopupState } from '@components/popup/ConfirmPopup.ts';
 
@@ -14,6 +14,14 @@
   });
 
   // callback
+  function onUserBlock(user: User) {
+    $confirmPopupState = {
+      title: 'Nutzer sperren?',
+      message: 'Soll der Nutzer wirklich gesperrt werden?\nEin gesperrter Nutzer kann dem Server nicht mehr beitreten.',
+      onConfirm: () => blockUser(user)
+    };
+  }
+
   function onUserDelete(user: User) {
     $confirmPopupState = {
       title: 'Nutzer löschen?',
@@ -27,6 +35,14 @@
   <span>{value.charAt(0).toUpperCase() + value.slice(1)}</span>
 {/snippet}
 
+{#snippet blockAction(user: User)}
+  {#if user.uuid}
+    <button class="cursor-pointer" onclick={() => onUserBlock(user)}>
+      <span class="iconify iconify-[heroicons--no-symbol]"></span>
+    </button>
+  {/if}
+{/snippet}
+
 <DataTable
   data={users}
   count={true}
@@ -39,6 +55,7 @@
     { key: 'edition', label: 'Edition', width: 5, sortable: true, transform: edition },
     { key: 'uuid', label: 'UUID', width: 23 }
   ]}
+  extraActions={blockAction}
   onEdit={(user) => (editPopupUser = user)}
   onDelete={onUserDelete}
 />
diff --git a/src/app/admin/users/users.ts b/src/app/admin/users/users.ts
index 665765a..35cf7f4 100644
--- a/src/app/admin/users/users.ts
+++ b/src/app/admin/users/users.ts
@@ -58,6 +58,16 @@ export async function editUser(user: User) {
   updateWritableArray(users, user, (t) => t.id == user.id);
 }
 
+export async function blockUser(user: User) {
+  if (!user.uuid) return;
+
+  const { error } = await actions.user.addBlocked({ uuid: user.uuid, comment: null });
+  if (error) {
+    actionErrorPopup(error);
+    return;
+  }
+}
+
 export async function deleteUser(user: User) {
   const { error } = await actions.user.deleteUser({ id: user.id });
   if (error) {
diff --git a/src/components/admin/table/DataTable.svelte b/src/components/admin/table/DataTable.svelte
index e57ad9e..afb8485 100644
--- a/src/components/admin/table/DataTable.svelte
+++ b/src/components/admin/table/DataTable.svelte
@@ -21,10 +21,11 @@
     onClick?: (t: T) => void;
     onEdit?: (t: T) => void;
     onDelete?: (t: T) => void;
+    extraActions?: Snippet<[T]>;
   }
 
   // input
-  let { data, count, keys, onClick, onEdit, onDelete }: Props<any> = $props();
+  let { data, count, keys, onClick, onEdit, onDelete, extraActions }: Props<any> = $props();
 </script>
 
 <div class="max-h-screen overflow-x-auto">
@@ -39,7 +40,7 @@
             >{key.label}</SortableTh
           >
         {/each}
-        {#if onEdit || onDelete}
+        {#if onEdit || onDelete || extraActions}
           <SortableTh style="width: 5%"></SortableTh>
         {/if}
       </SortableTr>
@@ -59,8 +60,11 @@
               {/if}
             </td>
           {/each}
-          {#if onEdit || onDelete}
-            <td class="px-3">
+          {#if onEdit || onDelete || extraActions}
+            <td class="px-3 whitespace-nowrap">
+              {#if extraActions}
+                {@render extraActions(d)}
+              {/if}
               {#if onEdit}
                 <button class="cursor-pointer" onclick={() => onEdit(d)}>
                   <span class="iconify iconify-[heroicons--pencil-square]"></span>
diff --git a/src/pages/api/users/[...uuid]/index.ts b/src/pages/api/users/[...uuid]/index.ts
index bb489e6..ce67f29 100644
--- a/src/pages/api/users/[...uuid]/index.ts
+++ b/src/pages/api/users/[...uuid]/index.ts
@@ -4,7 +4,12 @@ import { db } from '@db/database.ts';
 export const GET = externalApi({
   auth: true,
   handler: async ({ params }) => {
-    const user = await db.getUserByUuid({ uuid: params['uuid']! });
+    const uuid = params['uuid']!;
+
+    const blockedUser = await db.getBlockedUserByUuid({ uuid });
+    if (blockedUser) return new Response(null, { status: 403 });
+
+    const user = await db.getUserByUuid({ uuid });
     if (!user) return new Response(null, { status: 404 });
 
     const strikes = await db.getStrikesByUserId({ userId: user.id });