One of the reasons given against a pardon for Alan Turing in a November 2011 blog post by John Graham-Cumming (who successfully campaigned for a Turing apology in 2009) was that the Protection of Freedoms bill, if passed, would make a pardon unnecessary. This is because this
specifically allows for the disregarding of convictions under the old law that was used against Turing. Once disregarded the law causes their convictions to be deleted. It’s not quite the same thing as a pardon, but its effect is to lift the burden of a criminal record from these living men.
Now the bill has gained Royal Assent, becoming the Protection of Freedoms Act 2012. A short piece in The Independent calls this “a freedom too late” for Alan Turing. The Turing pardon e-petition now has over 33,000 signatures.
Source: Protection of Freedoms Bill.