The shutdown does not appear to be a spontaneous event, given that the Telecom Egypt, Raya, Link Egypt, Etisalat Misr and Internet Egypt ISPs each shut down its part of Egypt's Internet in sequence an average of about three minutes apart, according to Manchester, N.H.-based network security firm Renesys Corp. This sequencing indicates that each of the ISPs may have received a phone call telling them to drop Internet access to their subscribers, as opposed to an automated system that kicked in to take down all of the providers at once, Jim Cowie, Renesys chief technology officer and co-founder, blogged on Friday.