Instagram/instagram-ruby-gem — pull request #75 by toctan (2013-06-08 16:06:21+00:00)
Title: Improve the subscription process signature verification

```ruby
Instagram.process_subscription(params[:body], params["X-Hub-Signature"]) do |h|
# hi
end
```
With the above code, if a malicious request does not have a X-Hub-Signature header, the signature verification would be bypassed.