Interestingly, NoScript addon for Firefox brings up the following message on attempting the URL: "javascript: and data: URIs typed or pasted in the address bar

Interestingly, NoScript addon for Firefox brings up the following message on attempting the URL: "javascript: and data: URIs typed or pasted in the address bar are disabled to prevent social engineering attacks. Developers can enable them for testing purposes by toggling the "noscript.allowURLBarJS" preference."