The defamation act
The Defamation Act 1996 was created with the purpose of protecting individuals or organisations from slander and libel. Defamation occurs when untrue, damaging information about someone is published to a third party. If the Act is violated, the courts may decide that the guilty party has to compensate the person who was defamed.
The Act applies to adults in the jurisdiction of the United Kingdom. This includes yourself and your employees, both as a company or as individuals, depending who was involved in the publishing and the form it took. Employees are equally responsible as employers for any decision to publish defamatory statements (Defamation Act 1996, s1 (4)).
Defences to charges of defamation include proving that the statement did not originate from the defendant, that they took reasonable care in relation to the publication, and that they were not aware that they were contributing to or causing defamation of the claimant
(Defamation Act 1996, s1 (1)). You cannot be charged with defamation for broadcasting or making copies of material containing a defamatory statement published by somebody else (Defamation Act 1996, s1 (3)). Be aware that private internet communication (e.g. IM, emails, social networking sites) can also be mediums for defamatory statements and even choosing to forward emails containing defamatory statements can be an act of defamation.
In Reynolds v Times Newspapers  it was shown that the mass media can apply the defence of “qualified privilege” to defamation cases, if criteria of “responsible journalism” are met. In Loutchansky v Times Newspapers  it was decided that the media could not use this defence, been responsible as outlined by Lord Nicholls.
A person who has been defamed cannot press charges if over one year has passed since the defamatory statement was published. However, Loutchansky v Times Newspapers  showed that in cases of online defamation, liability is effectively perpetual as every time the defamatory item is viewed online, it is seen by the law as a republication.
Defendants can offer to make an out-of-court settlement to compensate for any unpleasantness or damage caused by the defamation (Defamation Act 1996, s2). Winslet v Associated Newspapers Ltd  shows that if the offer of amends is not seen by the defendant to be adequate, even after acceptance of compensation, the case may still be heard and the defendant may be awarded further compensation by the court.
It is important to encourage employees to read the Defamation Act 1996 and ensure that the Act is easily accessible for revision in the workplace. Perhaps arrange a workshop by a legal professional for your employees to attend, where basic legal points can be outlined and any questions can be answered. Also, ensure that all documents or items are checked by someone other than the author before publication, preferably by multiple people so that inappropriate material can be removed or edited.
The general rule that you and your employees should aim to abide by is that if you wish to publish offensive or otherwise negative statements about an individual, ensure that all statements are true. This may require thorough research and you might even wish to include references to reliable sources in the publication to show you have been responsible.
Defamation Act 1996
Loutchansky v Times Newspapers  EWCA Civ
Reynolds v Times Newspapers  2 AC 127
Winslet v Associated Newspapers Ltd -  EWHC 2735 (QB)
EDWARDS, Lilian and WAELDE, Charlotte (eds). Law and the Internet, Third Edition. Portland, Oregon, USA, Hart Publishing.
LLOYD, Ian J (2008) Information Technology Law, 5th Edition. Oxford, OUP.