Before revision:  We also obtain an adversarially robust algorithm for the L_2-heavy hitters problem using \mathcal{O \mathcal{O} \left(\log n{\epsilon^2}\right) bits of space.
After revision:  We also obtain an adversarially robust algorithm for the L_2-heavy hitters problem using \mathcal{O} \left(\log n{\epsilon^2}\right) bits of space.