It's based on the private parking company having to rely on contract law rather than statute, thus creating a fairly onerous set of legal requirements they have to satisfy before being able to enforce their charges.
All the details are [url=http://forums.pepipoo.com/index.php?s=a34f8904a75145b3c2444453dd6dbfa0&showtopic=46975here[/url and I can verify from personal experience that it works.
Private parking companies rely on fear, intimidation and ignorance - fight the power!
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