getty does this, so reassigning to util-linux. It appears to be intentional, as it's documented in the man page:
getty has several non-standard features that are useful for hard-wired and for dial-in lines: o Adapts the tty settings to parity bits and to erase, kill, end-of-line and uppercase characters when it reads a login name. The program can handle 7-bit characters with even, odd, none or space parity, and 8-bit charac- ters with no parity. The following special characters are recognized: @ and Control-U (kill); #, DEL and back space (erase); carriage return and line feed (end of line). ** Changed in: pam (Ubuntu) Sourcepackagename: pam => util-linux Status: Unconfirmed => Confirmed -- password prompt doesn't accept @ symbol https://launchpad.net/bugs/68988 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs