diff --git a/Classes/Domain/Model/Dto/ResolverData.php b/Classes/Domain/Model/Dto/ResolverData.php
index 54ed3e0..961af74 100644
--- a/Classes/Domain/Model/Dto/ResolverData.php
+++ b/Classes/Domain/Model/Dto/ResolverData.php
@@ -8,6 +8,8 @@
  * LICENSE.txt file that was distributed with this source code.
  */
 
+use T3Monitor\T3monitoring\Domain\Model\Rule;
+
 class ResolverData
 {
     /**
@@ -25,6 +27,11 @@ class ResolverData
      */
     protected $responseHeaders;
 
+    /**
+     * @var Rule
+     */
+    protected $rule;
+
     public function __construct(array $client, array $response, array $responseHeaders)
     {
         $this->client = $client;
@@ -79,4 +86,21 @@ public function setResponseHeaders(array $responseHeaders)
     {
         $this->responseHeaders = $responseHeaders;
     }
+
+    /**
+     * @return Rule
+     */
+    public function getRule()
+    {
+        return $this->rule;
+    }
+
+    /**
+     * @param Rule $rule
+     */
+    public function setRule(Rule $rule)
+    {
+        $this->rule = $rule;
+    }
+
 }
\ No newline at end of file
diff --git a/Classes/Resolver/BackendUserResolver.php b/Classes/Resolver/BackendUserResolver.php
new file mode 100644
index 0000000..1098a72
--- /dev/null
+++ b/Classes/Resolver/BackendUserResolver.php
@@ -0,0 +1,43 @@
+<?php
+namespace T3Monitor\T3monitoring\Resolver;
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+class BackendUserResolver extends BaseResolver
+{
+    const TITLE = 'Backend user';
+
+    public function setValueForComparison()
+    {
+        $this->valueForComparison = $this->resolverData->getResponse()['backendUser'];
+    }
+
+    public function getProviderArguments()
+    {
+        return GeneralUtility::trimExplode(PHP_EOL, $this->argument, true);
+    }
+
+    protected function isActiveOperator()
+    {
+        if (!isset($this->resolverData->getResponse()['backendUser'])) {
+            return;
+        }
+
+        $unwantedActiveUsers = array_intersect($this->getProviderArguments(),
+            $this->resolverData->getResponse()['backendUser']);
+
+        if (count($unwantedActiveUsers) > 0) {
+            $this->addRuleData($unwantedActiveUsers);
+        }
+        return $unwantedActiveUsers !== 0;
+    }
+
+    protected function addRuleData($backendUsers)
+    {
+        $update = $this->resolverData->getResponse();
+        $messageCategory = $this->resolverData->getRule()->getMessageCategory();
+        $update['extra'][$messageCategory][$this->resolverData->getRule()->getTitle()] = implode(',',
+            $backendUsers);
+        $this->resolverData->setResponse($update);
+    }
+}
\ No newline at end of file
diff --git a/Classes/Service/CheckResultService.php b/Classes/Service/CheckResultService.php
index 464815e..eaa3d4e 100644
--- a/Classes/Service/CheckResultService.php
+++ b/Classes/Service/CheckResultService.php
@@ -62,7 +62,11 @@ public function getProviderArguments()
         foreach ($checks as $check) {
             $providerArguments = $this->getResolver($check)->getProviderArguments();
             if ($providerArguments) {
-                $allProviderArguments[$check->getType()][] = $providerArguments;
+                if (is_array($providerArguments)) {
+                    $allProviderArguments[$check->getType()] = $providerArguments;
+                } else {
+                     $allProviderArguments[$check->getType()][] = $providerArguments;
+                }
             }
         }
 
@@ -82,6 +86,7 @@ public function createCheckResult(ResolverData $resolverData)
         $checkResult->setClient($resolverData->getClient()['uid']);
 
         foreach ($this->rules as $rule) {
+            $this->resolverData->setRule($rule);
             $checkFailureCriterias = true;
             foreach ($rule->getExecutionCriteria() as $executionCriteria) {
                 $checkFailureCriterias = $this->runCheck($executionCriteria);
diff --git a/Classes/Service/Import/ClientImport.php b/Classes/Service/Import/ClientImport.php
index cb0acb5..77d55b7 100644
--- a/Classes/Service/Import/ClientImport.php
+++ b/Classes/Service/Import/ClientImport.php
@@ -137,8 +137,10 @@ protected function importSingleClient(array $row)
                 'error_count' => 0
             ];
 
-            $checkResultCreationDemand = new ResolverData($row, $json, $responseHeaders);
-            $checkResult = $this->checkResultService->createCheckResult($checkResultCreationDemand);
+            $resolverData = new ResolverData($row, $json, $responseHeaders);
+            $checkResult = $this->checkResultService->createCheckResult($resolverData);
+            $json = $resolverData->getResponse();
+
             $update['earlier_check_result'] = $row['check_result'];
             $update['check_result'] = $checkResult->getUid();
 
diff --git a/Configuration/TCA/tx_t3monitoring_domain_model_check.php b/Configuration/TCA/tx_t3monitoring_domain_model_check.php
index 4931ed2..e4e819c 100644
--- a/Configuration/TCA/tx_t3monitoring_domain_model_check.php
+++ b/Configuration/TCA/tx_t3monitoring_domain_model_check.php
@@ -100,6 +100,24 @@
                 ]
             ]
         ],
+        'backendUser' => [
+            'showitem' => 'hidden, title, type, argument, operator',
+            'columnsOverrides' => [
+                'argument' => [
+                    'label' => 'List of backend users separated by newline',
+                    'config' => [
+                        'type' => 'text'
+                    ]
+                ],
+                'operator' => [
+                    'config' => [
+                        'items' => [
+                            ['is active', 'isActive'],
+                        ]
+                    ]
+                ],
+            ]
+        ],
     ],
     'columns' => [
         'hidden' => [
diff --git a/ext_localconf.php b/ext_localconf.php
index 95451ff..8273658 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -12,6 +12,7 @@ function ($extKey) {
         $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['processDatamapClass'][$extKey]
             = \T3Monitor\T3monitoring\Hooks\DataHandlerHook::class;
 
+        $GLOBALS['TYPO3_CONF_VARS']['EXT'][$extKey]['resolver']['backendUser'] = \T3Monitor\T3monitoring\Resolver\BackendUserResolver::class;
         $GLOBALS['TYPO3_CONF_VARS']['EXT'][$extKey]['resolver']['configurationValue'] = \T3Monitor\T3monitoring\Resolver\ConfigurationResolver::class;
         $GLOBALS['TYPO3_CONF_VARS']['EXT'][$extKey]['resolver']['header'] = \T3Monitor\T3monitoring\Resolver\HeaderResolver::class;
         $GLOBALS['TYPO3_CONF_VARS']['EXT'][$extKey]['resolver']['extensionState'] = \T3Monitor\T3monitoring\Resolver\ExtensionStateResolver::class;
diff --git a/ext_tables.sql b/ext_tables.sql
index c8c528b..b5ff28e 100644
--- a/ext_tables.sql
+++ b/ext_tables.sql
@@ -206,7 +206,7 @@ CREATE TABLE tx_t3monitoring_domain_model_check (
 
 	title varchar(255) DEFAULT '' NOT NULL,
 	type varchar(255) DEFAULT '' NOT NULL,
-	argument varchar(255) DEFAULT '' NOT NULL,
+	argument text DEFAULT '' NOT NULL,
 	operator varchar(255) DEFAULT '' NOT NULL,
 	value varchar(255) DEFAULT '' NOT NULL,