Those who oppose are doing so from a seriously small minority position. Complaints about the minutemen setting off sensors is laughable since thousands of illegals apparently don't set them off. (ignoring the possibility of ACLU types setting them off).
Complaints about illegals crossing in othere areas is another sign of success because the increased illegal traffic will irritate the fence sitters in those areas.
The Minuteman Project organizers worked with Border Patrol to ensure that the observation posts were not near the sensors and that volunteers would avoid walking where they might activate the sensors. The Minuteman Project organizers have stated that the sensors are being activated by the ACLU "legal observers" and media types tromping through the brush where they should not be.
I've told you before that the migrants don't weigh nearly as much as the rather heavy set steroidal mistakes apparently do.