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Exhibit 21.1

Protection One, Inc.
Exhibit 21.1—SUBSIDIARIES
December 31, 2009

Entity			Jurisdiction
Protection One Alarm Monitoring, Inc.			Delaware
	Network Multifamily Security Corporation		Delaware
	Security Monitoring Services, Inc. (d/b/a, CMS)		Florida
	Protection One Data Systems, Inc.		Delaware
	Protection One Systems, Inc.		Delaware
	Protection One Alarm Monitoring of Mass., Inc.		Massachusetts
	Integrated Alarm Services Group, Inc.		Delaware
		Integrated Alarm Services, Inc.	Delaware
		Criticom International Corporation	New Jersey
		Monital Signal Corporation	New Jersey
		National Alarm Computer Center, Inc.	Delaware

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Exhibit 21.1