Blocking abusive or fraudulent users online, may not be that easy.
An individual may create and use unlimited number of emails, phone numbers (fake or real), IP addresses, fake names to get passed the blocking. They may also have multiple credit cards or virtual cards, and may have multiple billing addresses.
So, blocking a user just by email is not effective.
Smart-block, tries to use all these information to identify a blocked user, prevent their future purchases, and collect new information from the blocked user to automatically add to the block list.
You can smart-block a user from Control Panel > Account & Settings > User Manager. Similarly, you can unblock a smart-blocked user.
To most effectively block a user from future purchases, do not block or delete the user. Just use the smart-block functionality.
When you Smart-Block a user, the system uses all their information, including all the information provided in the previous purchases, and add them to the block list.
You can see all the records in your block-list from Control Panel > Reports > Smart Block. You can also delete a record from the block-list.
When a user tries to make a purchase, the system tries to match their provided information with the ones in the block list. If it finds a match, it blocks the purchase with a generic error and adds all the provided information to the block list, as blocked by 'System'. It also marks the computer / device as blocked.
The generic error starts with an error code that looks like SMTBL-12345, where 12345 is the id of record that was matched as blocking record. You can use the report to potentially troubleshoot a blocked purchase.