therefore often under the jurisdiction of a nation other than where the service provider is located. Libya, for instance, exercised its control over the .ly domain in October 2010 to shut down vb.ly for violating Libyan pornography laws. Failure to predict such problems with URL shorteners and investment in URL shortening companies may reflect a lack of due diligence. Blocking and banning Some websites prevent short, redirected URLs from being posted. In April 2009, TinyURL was reported to be blocked in Saudi Arabia. Yahoo! Answers blocks postings that contain TinyURLs, and Wikipedia does not accept links by any URL shortening services in its articles. The Reddit community strongly discourages and in some subreddits, outright bans URL shortening services for link submissions, because they disguise the origin domain name and whether the link has previously been submitted to Reddit, and there are few or no legitimate reasons to use link shorteners for Reddit link submissions. Privacy and security A short URL obscures the target address and can be used to redirect to an unexpected site. Examples of this are "rickrolling", and redirecting to shock sites, or to affiliate websites. The short URL can allow blocked URLs to be accessed, bypassing site blocklists; this facilitates redirection of a user to blocked scam pages or pages containing malware or XSS attacks. TinyURL tries to disable spam-related links from redirecting. ZoneAlarm, however, has warned its users: "TinyURL may be unsafe. This website has been known to distribute spyware." TinyURL countered this problem by offering an option to view a link's destination before using a shortened URL. This ability is installed on the browser via the TinyURL website and requires the use of cookies. A destination preview may also be obtained by prefixing the word "preview" to the TinyURL URL; for example, the destination of is revealed by entering . Other URL shortening services provide a similar destination display. Security professionals suggest that users check a short URL's destination before accessing it, following an instance where the shortening service cli.gs was compromised, exposing millions of users to security uncertainties. There are several web applications that can display the destination URL of a shortened URL. Some URL shortening services filter their links through bad-site screening services such as Google Safe Browsing. Many sites that accept user-submitted content block links, however, to certain domains in order to cut down on spam, and for this reason, known URL