Can a regular user find out processes of another user (regular or superuser)

Researching through posts, I noticed that any user can query system to find out processes that belong to others. Wondering, if it is possible to restrict this ability i.e. a user can only find out processes that belong to them. The same question applies to other resources if they are treated in a similar manner i.e. everyone can see how many CPUs/Memory is being used by other users.