I have them, I hate them and would gladdly run a chain saw along the bottom of them at ground level if only I wouldn't loose my privacy on all sides. Worst ever species.
Other than get rid of them altogether, get them cut down to about 6-8 feet and try to keep them at that level. Ideally they should be cut 2-3 times every summer, I couldn't be bothered and usually pay someote to butcher mine once a year half hoping they will damage them so much that they will die and I will just have to get rid of them and replace them.