Definitely the ads causing most of this. Most of the ads on my pages look like this:
script language="JavaScript" type="text/javascript" src="http://view.atdmt.com/D2T/jview/178040521/direct;wi.300;hi.250/01/1861285415?click=http://googleads.g.doubleclick.net/aclk%3Fsa%3Dl%26ai%3DB1RwXJxPYSsCUO6qoqAPEp_HiAsfU y58B4ZapwBCXuPWlAwAQARgBINOg5gk4AFCAx-HEBGDJ9viGyKOgGbIBEXd3dy5mbHllcnRhbGsuY29tugEKMzAw eDI1MF9qc8gBCdoBXWh0dHA6Ly93d3cuZmx5ZXJ0YWxrLmNvbS 9mb3J1bS90ZWNobmljYWwtaXNzdWVzLzEwMDY0MjAtbGF5b3V0 LXNob290aW5nLW9mZi1lZGdlLW1vbml0b3IuaHRtbJgCzhO4Ah jAAgHIAun_xQyoAwHoA8sB6AO_AegD7QL1AwABAIQ%26num%3D 1%26sig%3DAGiWqtxmgaIcnBb8WfEdGhoqdf9p3-rrKQ%26client%3Dca-ib_travel_sede_1%26adurl%3D">