Colonizing within another players borders!

[Blackwind]

hi i noticed when i was testing the new update had discover that the AI that i was allied to was moving a colonizer though my territory even tho i was in the corner of the map so i thought this was strange and watching it when it plopped a city right in the middle of my city's.

i think as a general rule in these types of games is that you can not build a city in someone elses colony i mean it like Brittan building the city on Landon in the middle of France or something.