Well, the cardinals sew the ballots together with needle and thread during a papal election after they're announced aloud. Maybe it's something like that.
Most of the time I don’t comment on the atrocious grammar-but when it is a major publication, you’d expect that they could proofread-it should be “sowing complaints”-as in planting them like seeds-like sowing the seeds of discontent-not sewing with needle and thread...