Problem to solve
Some users do not make any edits, but only thanks to the single administrator. The purpose of these users is only to harass the administrator, and let him disturbed by a large number of notices.
Social sanctions can keep them in check, but currently the only technical means to corral this type of behavior is a full site block, which is extreme for some situations.
Proposed solution
It would be useful to be able to *only* block users from sending thanks on specific user.
In fact, this is very similar to T242785, But this task is limited to a specific user.