Madrid's High Court is set to turn its attention to Spain's music biz this fall as several groups prepare appeals against a digital tax on all new gadgets capable of recording, copying or storing digital sound and images.

The so-called "digital canon" was introduced on July 1, around 18 months after its scheduled date, despite protests and sometimes angry debate involving collecting societies, manufacturers and internet users.

The Internet Users Association (AI) took the lead and presented its appeal to the High Court on Aug. 1. Now several other groups say they will make the same move before the end of September's legal deadline. The cases will take at least a year to be resolved.

The tax is designed to compensate authors and creators for private copying of their work for personal use. But it is increasingly viewed as an anti-piracy tax in general.

"It is a tax that goes against the presumption of innocence because it takes for granted that somebody who buys, for example, a USB flash [drive] is going to use it necessarily to copy a song or a record," says AI president Victor Domingo. The AI's appeal says the "digital canon" law is unconstitutional because it contravenes articles covering legality, freedom of company, defence of productivity, cultural protection and the regulation of professional organisations.

Examples of the tax are €1.10 ($1.65) on mobile phones with integrated MP3 music devices; €3.40 for a CD/DVD recorder ($5.11); €3.15 ($4.73) per MP3 player and €0.17 per CD-R (25 cents).

Among those who say they are preparing appeals are consumer electronics manufacturing organisation Aetic and several mobile phone companies which are deciding whether to present a joint appeal or to do so individually. The protest website ("everybody against the canon") has gathered more than 500,000 online signatures against the tax.