according to Ghostery: "Because we had to use a 3rd party provider to make Ghostery for IE work efficiently, there are some smaller virus protection software makers that might mark it as against their rules (we’re actively working on this) .... Unfortunately, we cannot make an efficient extension for IE without using the Crossrider platform. We have tried in the past. Our other extensions don't rely on intermediary platforms." - also see "A Popular Ad Blocker Also Helps the Ad Industry"