Cacher is the code snippet organizer for pro developers

<?php
add_filter( 'gform_field_validation', 'wphacks_prevent_fake_phone_numbers', 1, 4);
function wphacks_prevent_fake_phone_numbers( $result, $value, $form, $field ){
	$error = array( 'is_valid' => 0, 'message' => 'Please use a real phone number' );
	
		//the 3 built in phone number fields, phone and text with input masks
		if ( ($field->type == 'phone') || ( $field->type == 'text' && $field['inputMaskValue'] == '(999) 999-9999? x99999' ) || ( $field->type == 'text' && $field['inputMaskValue'] == '(999) 999-9999' ) ){

		//remove all special characters to make a numbers only string
		$numbers_only = implode("", array_filter(str_split($value),function($array){ return is_numeric($array); }));
		
		//enter bad phone numbers here, without any symbols
		$bad_phone_numbers = array(
			'0111111111',
			'1234567890',
			'0123456789',
			'5555551212',
		);
		if(in_array($numbers_only, $bad_phone_numbers)){
			return $error;
		}
		
		//this keeps 
		if(count( array_unique( array_filter( str_split( $value ),function( $array ){ return is_numeric( $array ); } ) ) ) === 1 ){
			return $error;
		}

		//this keeps out real area codes with 7 of the same digits
		if(count( array_unique( array_filter( str_split( substr( $numbers_only, 3) ),function( $array ){ return is_numeric( $array ); } ) ) ) === 1 ){
			return array( 'is_valid' => 0, 'message' => 'Please use a real phone number'. substr( $numbers_only, 3, 0 ) );
		}
	}
	return $result;
}
?>