It's not a technical loop hole. The law basically says; "if there is a fax number on a web site, you may send a fax to that number unless the site says otherwise." If I "piss off the wrong person" - that person will unfortunately have wasted time and energy that they could have otherwise spent having their tech guy slap the line; "no unsolicited faxes" on their site.

The answer to your question is "Yes." Good code never fails. If you open up Microsoft Word, and you type up a 1,000 page document, then run a search for the word "and" will MS Word pick up every single instance of the word "and," or will it miss some? Same principle here...

Running methods to scrape the internet for fax numbers, and associating them with URL's and corresponding META Data was not too difficult. Time consuming, but not difficult. Writing custom methods for referencing those URL's with a coterie of API's (where the data cannot be downloaded) in order to parse it / scrub it against string variables like "do not" or "unsolicited" was slightly tougher - but equally time consuming.