Arlington’s Solid Waste Bureau offers “free paper document shredding” every month. Watch old medical records, credit card receipts, tax returns, and the like being turned into harmless confetti. It is enough to make an identity thief cry. Scraps are recycled, so some trees are also saved. The shredding takes place on the first Saturday of the month from 8 a.m. to 4:30 p.m. at the county yard, 4300 29th Street, South (near Shirlington, off South Arlington Mill Road). Next event is April 2.