is there anyway to prevent villagers from moving in from online visitors?

[zola]

i trade often, so i have a lot of players come to my island through online play. i recently had an open plot and a villager moved in from an island belonging to someone that i had traded with. is there any way to prevent this?

 

[JKDOS]

No. As soon as you go online, voided villagers and potential ones are saved to your save file.