You can register multiple accounts by changing case in email. For example: email@gmail.com and Email@gmail.com perceived as a different mail in database.
@Garazd @IgorMaksymov @AndriyBaibak @alex-anakin According to Wikipedia email@gmail.com and Email@gmail.com are different emails. As I understood, case insensitive only part of address after @. So I propose to clarify the wording of this issue.
You can register multiple accounts by changing case in email. For example: email@gmail.com and Email@gmail.com perceived as a different mail in database.