There are laws that have passed in the EU that allow citizens in the EU the right to request the deletion of personal information from any website in the world should they feel like it. This of course is only if that information is not part of a criminal investigation or a breach of freedom of speak or in the public's interest. A case is currently in progress against Google by the EU Central Courts about Google failing to obey EU user's requests to do exactly that.
In other words if the guy asks you to delete his account, you have to do it unless there is a really good reason not too i.e. a legal reason.
http://ec.europa.eu/justice/data-protection/files/factsheets/factsheet_data_protection_en.pdf
How do I know this, I have to obey this law myself as part on my job.
Amendment
http://www.telegraph.co.uk/technolo...ies-affected-by-EU-right-to-be-forgotten.html
Apparently Google can retain the information about the event as it is part of public record but must remove any links to it as part of the ruling or suffer a fine. Obviously we all know that this is effectively deleting the article for all intensive purposes. I figure it is the comprise that the EU are willing to put up with to protect the integrity information and data VS the personal rights of the citizens.