This bug may be a security issue, because i had the following experience:
I was working in a terminal window with elevated privileges when i locked my computer to go for a meeting.
When i came back i couldn't log in because LightDM seemd not to capture my keyboard. After some clicking around and trying i finally could log in again and saw that everything i typed was entered in the terminal window as plain text.
This bug may be a security issue, because i had the following experience:
I was working in a terminal window with elevated privileges when i locked my computer to go for a meeting.
When i came back i couldn't log in because LightDM seemd not to capture my keyboard. After some clicking around and trying i finally could log in again and saw that everything i typed was entered in the terminal window as plain text.
I hope this gets solved soon.