Everybody noticed how rapidly the porn charges were dropped in the Rolf Harris case. It has been known for years that planting drugs became a rather useless trick played by Renta-Cop and they switched to dumping porn images onto seized computers. I suspect however, in 2008 this was not known and Damian Green didn't do (as many do now) the obvious - on getting his computers returned, have them independently analysed (these days the same forensic firm that police use, since that department was cut back by budget restrictions).

Incredibly hard to do these days and get away with it.
Until smart phones arrived it was easy to change dates etc on when a photo was taken on a mobile phone ie let's say you need a photo date to fit a time which could make a conviction, someone was 15 and 363 days or 16 and 2 days one would make sexual contact a crime the other gets a not guilty.
What could you do to aid a conviction? Easy.
By using Bluetooth send the image to another phonew then change the date on the phone you need the evidence date to then Bluetooth the image back it then gave the image a new date and time, simples!
The forensic officer would then say in court that most probably the photo was taken with that phone and on that date when in fact it WAS taken on that phone but not on that date it also worked for downloaded photos in the same way but not on the new smart devices.

Yes I think that's why this false allegation dates back to 2008. But you can be sure there are some dim cops in the sticks trying the same trick - unaware that judges now regard this sort of behaviour as conspiring to pervert the course of justice.

When oh when is someone going to look at the bigger problem - the false allegations industry? Kate Hoey mentioned this on Marr.

How do you know that this porn was planted jk, you don't. Anyhow as long as the porn isn't illegal there shouldn't be a problem. I think most people would have looked at legal porn at some time or another. I noticed that he says that there wasn't any extreme pornography on his computer, implying that there was some non-extreme porn.

I came across a case of 'planting evidence' about ten years ago. A barrister friend dropped the name of a top computer expert, and the CPS backed away from the case, saying they were now unsure how certain images came to be on the computer. At the time, I was a part time writer for a local paper, but the editor said the story would not be in the public interest.