We've had a sudden rash of students who want to switch sections. Reasons have ranged from "My best friend is in so and so's section and I want to be with her" to "My instructor hates me". I have to tell you, my answer to those students is almost always no. There are several reasons for my position.
The first is pedagogical - at this time in the term you've already done a lot of community building work with your students, so subtracting one from one section and adding one to another section can create problems for the classes, particularly if the new section uses any group work. Students with friends in a different section can also have all the benefits of discussing the course material with those friends, but with different assignments for grading purposes.
Then there is the practical side - students who switch sections either lose the work they have completed in the first section or require extra work on the part of both instructors to pass those grades over along with the student. It also creates work for John, Roxanne, and David, none of whom need more to do.
And lastly, the financial side - COF has made it difficult and frequently impossible for us to move students around after census day without causing the student to lose their COF funds for the section they moved from. (COF is the $80 or so the student receives from the state of Colorado to supplement standard tuition. It replaces the old FTE reimbursement system. Students have a limited number of COF dollars attached to their names.)
So...... unless the faculty and the student are at odds in such a way that causes me to believe that the learning environment for the student has been irretrievably ruined I tend to say no to section switching requests.