Looking into your family tree is a common hobby and is usually done using a genealogy site. This is different from DNA testing that provides information about racial background and rarely relates to specific ancestors.
If your loved one used these sites, there are a few reasons you would want to look into their activities.
When you know your loved one’s password and username or email you must login to their account to begin the process.
Password and email/username known
Password and email/username unknown — Go to Ancestry Account Support to inquire about deleting their subscription and accessing the content.
Password and email unknown — Contact Archives Customer Support, send them an email, or call them at 888-896-4442 to inquire about accessing and closing their account.
Password and username unknown — Contact Family Search Customer Support, send them and email, or call them at 866-406-1830 to inquire about accessing and closing their account.
Password and account number known
Password and username unknown — Contact MyTrees by email or or call them at 801-229-7967 to inquire about accessing and closing their account.
When you discontinue their subscription it is still active until the time that they have paid for has expired.