Some colleges are transparent about it. For example:
http://www.sjsu.edu/admissions/impaction/index.html
But others are not transparent about it, or even whether intended major is a consideration.
However, getting admitted to an easier-admissions major is not helpful if it means that you will have to apply competitively to get into your actual desired major after enrolling.
The main use of this information is so that you can make better reach/match/safety estimates. For example, a prospective CS major may need an application list that is generally lower on the selectivity scale than an applicant for most other majors, since CS is a more selective major at many colleges.