Yandex Metrica automatically assigns a ClientID to each unique site user. This ID is anonymous: it is randomly generated and identifies the browser that was used to view the site. This means that if the same user viewed your site from two different browsers, two different ClientIDs will be registered in Yandex Metrica.
If necessary, you can assign your own IDs to your site users and transmit them to Yandex Metrica as the UserID.
Please note: Our support team will never initiate a call to you. Do not follow any instructions of people who call you and introduce themselves as the Yandex Metrica support team.