Social Media

The Register – @TheRegister

https://twitter.com/theregister
Twitter profile: Biting the hand that feeds IT. Technology and science news for world+dog. 
Follow us: Science and technology news for the world

Naked Security – @NakedSecurity

https://twitter.com/NakedSecurity
Twitter profile: Award-winning security news, opinion, advice and research from Sophos
Follow for: Security Industry news and views

LinkedIn

InfoSec Careers (Information Security)

https://www.linkedin.com/groups/1364287/profile

InfoSec Careers is dedicated to connecting Information Security and Cyber professionals interested in a new permanent career opportunity or contracting jobs with specialist recruiters and hiring managers looking for new talent. This is THE LinkedIn Group for Cyber & Information Security Jobs and all those interested in IT Security news from industry.

This group is specifically relevant for those professionals holding CISM, CISA, CREST, BS7799 / ISO27001 Lead Auditor, CISSP, GIAC, PCI QSA, CRISC, CLAS or similar certifications.

Type: Networking Group
Members: 9,120 

Jericho Forum

The Jericho Forum is an international IT security thought-leadership group dedicated to defining ways to deliver effective IT security solutions that will match the increasing business demands for secure IT operations in our open, Internet-driven, globally networked world. 
This Linkedin group only indicates interest - for actual Jericho Forum members see https://www.opengroup.org/jericho/memberCompany.htm.

Type: Professional Group
Members: 1,057
https://www.linkedin.com/groups?home=&gid=47229

SC Magazine UK (Information Security)

https://www.linkedin.com/groups/1833658/profile

This group is open to professionals working in information security and risk management and is affiliated to SC Magazine and SC branded events including conferences. The SC brand provides information and intelligence for professionals working in information and organisational security.

Its followers include FTSE 100 CISOs and CSOs who are relied upon to protect their businesses from the wide-ranging data threats that exist in the world today.

Type: Networking Group
Members: 6,334

Blog

Krebs on Security

http://krebsonsecurity.com/
In-depth Security news and investigation

SecurityWatch

http://bhconsulting.ie/securitywatch/
Brian is recognised internationally as an expert in the field of information security and has worked with numerous companies in the private sector and with government departments, in Ireland, Europe and throughout the United Kingdom. Brian has also provided advice to the European Commission on matters relating to information security. He is also on the advisory board for a number of innovative information security companies.

Schneier on Security

https://www.schneier.com/
Bruce Schneier is an internationally renowned security technologist, called a "security guru" by The Economist. He is the author of 12 books -- including Liars and Outliers: Enabling the Trust Society Needs to Thrive -- as well as hundreds of articles, essays, and academic papers. His influential newsletter "Crypto-Gram" and his blog "Schneier on Security" are read by over 250,000 people.