That's not true. There are at least seven four storey buildings (Alza, Crittenden) on the main campus, and there's also a new 5 storey building on Pear Ave. But almost none of their buildings were built new, most were already built and acquired. Their proposals for new buildings have mostly been around 6-8 storeys, but they've had problems getting the city to approve their plans. I believe the LinkedIn land they acquired also already has approval for taller buildings.