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William RM Long

William RM Long
Woolgate Exchange
25 Basinghall Street
+44 20 7360 2061
+44 20 7626 7937


Who's Who Legal Telecommunications Media & Technology: Information Technology

William Long leads the EU data protection practice at Sidley Austin and advises international clients on a wide variety of data protection, privacy, information security, social media, e-commerce and other regulatory matters. 

William has been a member of the European Advisory Board of the International Association of Privacy Professionals (IAPP) and is on the DataGuidance panel of data protection lawyers. He is also on the editorial board of e-Health Law & Policy and assists with dplegal (“data privacy” legal), a networking group of in-house lawyers in life sciences companies examining international data protection issues.

Representative matters have included advising a global e-commerce company on dealing with an international data security breach; assisting a global manufacturing company with a global data protection project including implementation of Binding Corporate Rules; and assisting a global medical device manufacturer with a global data protection project including implementation of binding corporate rules, dealing with cross-border data transfer issues and assisting with data protection filings.

William was previously in-house counsel to one of the world’s largest international financial services groups. He has been a member of a number of working groups in London and Europe looking at the EU regulation of e-commerce and data protection and spent a year at the UK’s Financial Law Panel (established by the Bank of England) as assistant to the chief executive, working on regulatory issues with online financial services.

William is recognised in Chambers UK 2016 for data protection and information law, with sources telling the publication he is “very knowledgeable,” has “his finger on the pulse” and “a very good collaborative spirit.” He is also recognised in the LMG Life Sciences Guide for Intellectual Property and Who’s Who Legal 2017 for TMT. Most recently, William is recognised for both data protection and pharmaceuticals and biotechnology in The Legal 500 UK 2016, with clients describing him as “a very able lawyer who provides high-quality, practical advice.” He is also listed in the 2017 edition of Best Lawyers for privacy and data protection.

William is also the author of a new book on the EU general data protection regulation and is a contributor to a number of books on data protection, including leading legal text books published by BNA in the area of privacy, cloud computing and the use of health data. William has been interviewed widely for his thought leadership, including in such leading publications as the International New York Times, Financial Times and The Guardian, and writes for a number of publications including Data Protection Law & Policy, Computer Weekly, Cloud Pro and CIO Today.

WWL says: Long is strongly endorsed by peers internationally for his EU data protection practice. 

This biography is an extract from Who's Who Legal: Telecommunications Media & Technology which can be purchased from our Shop.

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W11 1QQ, UK