Editing ICQ (section)

===Policy against unofficial clients===
[[AOL]] (and later Mail.ru) pursued an aggressive policy regarding alternative ("unauthorized") ICQ clients.
*In July 2008, changes were implemented on ICQ servers causing many unofficial clients to stop working. These users received an official notification from "ICQ System".
*On December 9, 2008, another change to the ICQ servers occurred: clients sending Client IDs not matching ICQ 5.1 or higher stopped working.
*On December 29, 2008, the ICQ press service distributed a statement characterizing alternative clients as dangerous.<ref>{{Cite web|url= http://www.cyberstyle.ru/newsline/4538-icq-qip-infium-jabber-miranda-mail.ru-agent-jimm-messenger-im-instant-messaging-aska-mgnovennye-soobseniy-klient.html|title= Официальное заявление ICQ: использовать QIP — опасно &#124; CyberStyle.ru|website= www.cyberstyle.ru}}</ref>
*On January 21, 2009, ICQ servers started blocking all unofficial clients in Russia and [[Commonwealth of Independent States]] countries.<ref>{{Cite web |url=http://profy.com/2009/01/21/aol-engaged-in-dubious-competition-practices-for-icq-in-russia/ |title=AOL Engaged in Dubious Competition Practices for ICQ in Russia |access-date=2009-02-04 |archive-date=2009-01-24 |archive-url=https://web.archive.org/web/20090124231815/http://profy.com/2009/01/21/aol-engaged-in-dubious-competition-practices-for-icq-in-russia/ |url-status=dead }}</ref> Users in Russia and Ukraine received a message from UIN 1:
<blockquote>
"Системное сообщение<br/>
:ICQ не поддерживает используемую вами версию. Скачайте бесплатную авторизованную версию ICQ с официального web-сайта ICQ.
System Message
:The version you are using is not supported by ICQ. Download a free authorized ICQ version from ICQ's official website."
</blockquote>
On icq.com there was an "important message" for Russian-speaking ICQ users: "ICQ осуществляет поддержку только авторизированных версий программ: ICQ Lite и ICQ 6.5." ("ICQ supports only authorized versions of programs: ICQ Lite and ICQ 6.5.")
*On February 3, 2009, the events of January 21 were repeated.
*On December 27, 2018, ICQ announced it was to stop supporting unofficial clients, affecting many users who prefer a compact size using [[Miranda NG]] and other clients.
*On December 28, 2018, ICQ stopped working on some unofficial clients.
*In late March, 2019, ICQ stopped working on the [[Pidgin (software)|Pidgin]] client, as initiated in December 2018.