1. A method comprising: detecting a request from a first domain to access a second domain; applying cross-domain access heuristics to determine whether to allow the request, the cross-domain access heuristics defining common ownership characteristics between the first domain and the second domain; performing the requested access in response to determining that the request complies with at least one of the cross-domain access heuristics; and blocking the requested access in response to determining that the request fails to comply with the cross-domain access heuristics.