diff --git a/tests/checks/test-VIPEscapingCheck.php b/tests/checks/test-VIPEscapingCheck.php
new file mode 100644
index 0000000..8655198
--- /dev/null
+++ b/tests/checks/test-VIPEscapingCheck.php
@@ -0,0 +1,101 @@
+<?php
+
+require_once( 'CodeCheckTestBase.php' );
+
+class VIPEscapingTest extends CodeCheckTestBase {
+
+	public function testEscaping() {
+		$lines = 3;
+
+		$expected_errors = array();
+
+	
+		/*
+		 * Why 4 * 5? Why a the loop?
+		 * Because we are specifying very similar
+		 * test-result, again and again.
+		 *
+		 * First, four tests for echo (without brackets)
+		 * 	echo __( ... );
+		 * 	echo _x( ... );
+		 *	echo _n( ... );
+		 * 	echo _nx( ... );
+		 *
+		 * Second, four similar tests for echo with brackets
+		 * Third, four similar tests for print without brackets
+ 		 * Fourth, four similar tests for print with brackets
+		 * Fifth, four simila tests for vprintf (with brackets)
+		 *
+		 * Note: If you find yourself adding 'ifs' within the
+		 * for-loop, stop using a loop and write out each
+		 * expected error individually.
+		 */
+
+		for ($i = 0; $i < 4 * 5; $i++) {
+			$expected_errors[] = array(
+				'slug' => 'functions-file',
+				'level' => BaseScanner::LEVEL_BLOCKER,
+				'description' => sprintf(
+					esc_html__( 'Printing output of non-escaping localization functions (i.e. %1$s) is potentially dangerous, as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ),
+					'<code>__( ), _x( ), _n( ), _nx( )</code>',
+					'<code>esc_html__( ), esc_attr__( ), esc_html_x( ), esc_attr_x( )</code>'
+				),
+				'file' => 'VIPEscapingTest.inc',
+				'lines' => $lines++,
+			);
+		}
+
+		$lines++;
+
+
+		/*
+		 * Now test for non-printing usage of __( ), _x( ),
+		 * _n( ), and _nx( ).
+		 *
+		 * Note: If you find yourself adding 'ifs' within the
+		 * for-loop, stop using a loop and write out each
+		 * expected error individually.
+		 */
+
+		for ($i = 0; $i < 4; $i++) {
+			$expected_errors[] = array(
+				'slug' => 'functions-file',
+				'level' => BaseScanner::LEVEL_WARNING,
+				'description' => sprintf(
+					esc_html__( 'Usage of non-escaping localization functions (i.e. %1$s) is discouraged as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ),
+					'<code>__( ), _x( ), _n( ), _nx( )</code>',
+					'<code>esc_html__( ), esc_attr__( ), esc_html_x( ), esc_attr_x( )</code>'
+				),
+				'file' => 'VIPEscapingTest.inc',
+				'lines' => $lines++,
+			);
+		}
+
+
+		/*
+		 * Now test for usage of _e( ), _ex( ).
+		 *
+		 * Note: If you find yourself adding 'ifs' within the
+		 * for-loop, stop using a loop and write out each
+		 * expected error individually.
+		 */
+
+		for ($i = 0; $i < 2; $i++) {
+			$expected_errors[] = array(
+				'slug' => 'functions-file',
+				'level' => BaseScanner::LEVEL_BLOCKER,
+				'description' => sprintf(
+					esc_html__( 'Usage of non-escaping localization functions (i.e. %1$s) is discouraged as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ),
+					'<code>_e( ), _ex( )</code>',
+					'<code>esc_html_e( ), esc_attr_e( ), esc_html_x( ), esc_attr_x( ), esc_attr__( )</code>'
+				),
+				'file' => 'VIPEscapingTest.inc',
+				'lines' => $lines++,
+			);
+		}
+
+
+		$actual_errors = $this->checkFile( 'VIPEscapingTest.inc' );
+		$this->assertEqualErrors( $expected_errors, $actual_errors );
+	}
+}
diff --git a/tests/data/VIPEscapingTest.inc b/tests/data/VIPEscapingTest.inc
new file mode 100644
index 0000000..c7ab068
--- /dev/null
+++ b/tests/data/VIPEscapingTest.inc
@@ -0,0 +1,30 @@
+<?php
+
+die(); //Don't actually run the following code.
+
+echo __( 'Message #1' );
+echo _x( 'Message #1' );
+echo _n( 'Message #1' );
+echo _nx( 'Message #1' );
+echo( __( 'Message #1' ) );
+echo( _x( 'Message #1' ) );
+echo( _n( 'Message #1' ) );
+echo( _nx( 'Message #1' ) );
+print __( 'Message #1' );
+print _x( 'Message #1' );
+print _n( 'Message #1' );
+print _nx( 'Message #1' );
+print( __( 'Message #1' ) );
+print( _x( 'Message #1' ) );
+print( _n( 'Message #1' ) );
+print( _nx( 'Message #1' ) );
+vprintf ( __( 'Message #%d' ), 1 );
+vprintf ( _x( 'Message #%d' ), 1 );
+vprintf ( _n( 'Message #%d' ), 1 );
+vprintf ( _nx( 'Message #%d' ), 1 );
+__( 'Message #1' );
+_x( 'Message #1' );
+_n( 'Message #1' );
+_nx( 'Message #1' );
+_e( 'Message #1' );
+_ex( 'Message #1' );
diff --git a/vip-scanner/checks/VIPEscapingCheck.php b/vip-scanner/checks/VIPEscapingCheck.php
new file mode 100644
index 0000000..5fff8f9
--- /dev/null
+++ b/vip-scanner/checks/VIPEscapingCheck.php
@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * Detect errors in escaping.
+ */
+class VIPEscapingCheck extends BaseCheck {
+	function check( $files ) {
+		$checks = array(
+			array(
+				/*
+				 * Catch printing usage of __( ), etc.
+				 * These are blockers because the results
+				 * are being printed without HTML-escaping the
+				 * results.
+				 */
+				'pattern' => '/([\s]|[;]){1,}(echo|vprintf|print)([\s]|[\(])+(__|_x|_n|_nx)[\s]*?\(/',
+				'level'   => 'blocker',
+				'message' => sprintf( 
+						esc_html__( 'Printing output of non-escaping localization functions (i.e. %1$s) is potentially dangerous, as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ), 
+						'<code>__( ), _x( ), _n( ), _nx( )</code>', 
+						'<code>esc_html__( ), esc_attr__( ), esc_html_x( ), esc_attr_x( )</code>' 
+				),
+			),
+			array(
+				/*
+				 * Catch non-printing usage of __( ), etc
+				 * These are warnings, because the results
+				 * are not being immediately printed, and so
+				 * could be escaped at a later point.
+				 */
+				'pattern' => '/([\s]|[;]|[=]){1,}[a-zA-Z]{0}[\s]+(__|_x|_n|_nx)[\s]*?\(/',
+				'level'   => 'warning',
+				'message' => sprintf( 
+						esc_html__( 'Usage of non-escaping localization functions (i.e. %1$s) is discouraged as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ), 
+						'<code>__( ), _x( ), _n( ), _nx( )</code>', 
+						'<code>esc_html__( ), esc_attr__( ), esc_html_x( ), esc_attr_x( )</code>' 
+				),
+			),
+			array(
+				/*
+				 * Catch calls to _e( ), _ex( )
+				 * These print directly, without HTML-escaping,
+				 * and so are blockers.
+				 */
+				'pattern' => '/([\s]|[;]){1,}[a-zA-Z]{0}[\s]+(_e|_ex)[\s]*?\(/',
+				'level'   => 'blocker',
+				'message' => sprintf( 
+						esc_html__( 'Usage of non-escaping localization functions (i.e. %1$s) is discouraged as they do not escape HTML. An escaping function (e.g. %2$s) should be used rather.', 'vip-scanner' ), 
+						'<code>_e( ), _ex( )</code>', 
+						'<code>esc_html_e( ), esc_attr_e( ), esc_html_x( ), esc_attr_x( ), esc_attr__( )</code>' 
+				),
+			),
+		);
+
+		$result = true;
+		foreach ( $checks as $check ) {
+			$this->increment_check_count();
+			foreach ( $this->filter_files( $files, 'php' ) as $path => $code ) {
+				$filename = $this->get_filename( $path );
+				$errors = $this->preg_file2( $check['pattern'], $code );
+				foreach ( (array) $errors as $line_number => $error ) {
+					$this->add_error(
+						'functions-file',
+						$check['message'],
+						$check['level'],
+						$filename,
+						array( $line_number => $error )
+					);
+					$result = false;
+				}
+			}
+		}
+		return $result;
+	}
+}
diff --git a/vip-scanner/config-vip-scanner.php b/vip-scanner/config-vip-scanner.php
index e9f688b..1aeb9ed 100644
--- a/vip-scanner/config-vip-scanner.php
+++ b/vip-scanner/config-vip-scanner.php
@@ -59,6 +59,7 @@
 	'DeprecatedFunctionsCheck',
 	'DeprecatedParametersCheck',
 	'jQueryCheck',
+	'VIPEscapingCheck',
 	'VIPWhitelistCheck',
 	'VIPRestrictedClassesCheck',
 	'VIPRestrictedPatternsCheck',