Consider the following scenario:
- The Unified Contact Store (UCS) feature is enabled in a Microsoft Lync Server 2013 organization.
- You sign in to Lync 2013, and then you select the Block all invites and communications check box in the organization.
- A Public IM Connectivity (PIC) or unverified user from a federated organization tries to view your presence status in Lync 2013. The user is not in your buddy list.