CPS drop charges against student chalker

I wrote previously about Bristol student Paul Saville who was arrested for criminal damage for writing a poem about liberty on the pavement  - in chalk.
Paul was due to appear before magistrates in Bristol this week but received a letter at the weekend telling him the CPS have dropped the charges.
Which is obviously a sensible conclusion to what would have been a colossal waste of time and money against someone exercising their right to free speech.
Paul's case was widely reported and united civil libertarians on the left and right. I'm not aware of anyone else getting the Guardian civil liberty hero of the week award and the conservative Young Britons' Foundation's hero of the week award.
However, Paul still has a DNA sample taken from a first arrest for chalking on a pavement where he was given a caution and that remains on file. Comedian and activist Mark Thomas explains in this video how you might go about clearing your DNA file from the national database.
I understand Paul still plans to have a gathering of his supporters outside Bristol Magistrates Court at 9.45am this Wednesday to protest against the way he has been treated and highlight some of the civil liberty questions his case throws up