Why is linkedIn adding a pound exclamation mark (hashbang) to my URL?

Question

When sharing a link I've noticed that linkedIn appends a '#!' to the end of the URL after redirecting. This is breaking my Backbone.js single-page app since we use pushstate in the URL, and so the '!' is interpreted as a Backbone.js route.

Here is an example link (not my site). It will take you to: http://blog.mindresearch.net/blog/bid/336633/The-Connection-Between-Math-and-Neuroscience# !

I know I can filter this on the server-side, or deal with it on the client-side in numerous ways, but it just seems strange, and I saw no posts online about this topic, so thought I'd post a question asking what it is, and whether there is a way to get rid of it?

Of course, I'll also email LinkedIn support, but thought this could be useful to anyone else running into the same problem.

Answer 1

AFAIK anything after the hash is not sent to the server; I use a simple client-side script to redirect those URLs. A naive redirect, but it works. I don't see any way of preventing it from occurring, unless LinkedIn and Facebook change their outgoing redirect policy.

<script>
  if( window.location.hash == '#!' ) {
    window.location.href = 'http://domain.tld/';
  }
</script>

Sure it only works for JavaScript enabled clients, but then again in my experience those hashbang URLs only break those clients in the first place.