I'm currently using Typekit, and had a problem with the include link no longer working. When I follow the include link
<script type="text/javascript" src="//use.typekit.net/xxxxxx.js"></script>
it renders an html page saying that it has been blocked by a BOTNET filter.
This site has been blocked by the network administrator.
Block reason: Gateway BOTNET Filter Alert
IP address: 72.21.92.19
Connection initiated towards Botnet server.
If you believe the below web site is rated incorrectly click here
Was Typekit hacked or did the IP address change and I just need to allow it from the firewall?
I contacted support for Typekit, and apparently they were using a cloud-based host, so that they were sharing an IP with a company that was sending malicious software. They contacted the service provider to remove the malicious company from the server, and were able to remove the IP from the list of botnet IP's (or changed their own IP so that it wasn't on the list).
In either case, this sounds like it might be a potential issue with using any cloud-based service.