What is Blacklist (computing)?
In [[computing]], '''blacklisting''' is a form of [[access control]]. A [[proxy server]] might check the list of pages accessed against a ''blacklist'', if the address is on the blacklist, the page cannot be accessed. [[File:Spam_tutorial_-_local_blacklisting.png|right|thumb|220x220px|Screenshot of a web page of a [[Wikimedia Foundation]] project. Filing a blacklisting request.]] ==Examples of systems protected== Blacklists are used to protect a variety of systems in computing. The content of the blacklist has to be targeted to the type of system defended.<ref>{{Cite web|title = Domain Blacklist Ecosystem - A Case Study|url = https://insights.sei.cmu.edu/cert/2015/06/domain-blacklist-ecosystem---a-case-study.html|website = insights.sei.cmu.edu|access-date = 2016-02-04}}</ref> ===Information systems=== An information system includes [[Host (network)|hosts]] like [[computer]]s and [[server]]s. A blacklist in this location may include certain types of software that aren't allowed to run in the company environment. For example, a company might blacklist worker to worker [[file sharing]] on its systems, to stop them editing worker information. In addition to software, people, devices and [[website]]s can also be blacklisted.<ref>{{cite book|last=Rainer | first=Watson|title=Introduction to Information Systems|url=https://archive.org/details/isbn_2901118063346 |year=2012|publisher=Wiley Custom Learning Solutions|isbn=978-1-118-45213-4}}</ref> ===Email=== Most email providers have an [[Spamming|anti-spam]] feature that essentially blacklists certain [[email address]]es if they are thought to be spam or [[Malware|malicious]]. For example, a user who gets of a lot of emails from a particular address, they may blacklist that address, and the email [[Client-server|client]] will automatically route all messages from that address to a junk-[[mail]] folder or delete them without telling the user. An e-mail spam filter may keep a blacklist of email addresses, any mail from which would be prevented from reaching its intende