According to e-Consultancy, one in three UK companies flout spam laws.
A study by CDMS claims 31% of the UK's top companies are failing to comply with current EU directives on Privacy and Electronic Communications.
They claim 69% of companies do comply, up only 3% on the last study in 2005. That said, they only polled 200 companies so maybe it was just a bad group.
The requirement for customers to opt-in is a crucial part of the EU laws. So too is the requirement for unsubsribe requests to be actioned instantly (and preferably automatically).
You can read the whole article here - One in three UK companies flout spam laws.