README.md in hightop-0.0.2 vs README.md in hightop-0.0.3

@@ -16,9 +16,11 @@
 
 ```ruby
 Visit.top(:referring_domain, 10)
 ```
 
+Be sure to [sanitize user input](http://rails-sqli.org/) like you must with `group`.
+
 ## Installation
 
 Add this line to your application’s Gemfile:
 
 ```ruby