AFAIK the petition website service is provided by an independednt IT firm. It most likely doesn't have the capacity to deal with the massive level of hits this petition has generated. However, that's not to say some nasty little person in the secret services has sabotaged it.
The BBC reporting has been an utter disgrace IMO, the internal lobbying from the right-on media greenies must be intense. Well bully for them, but I can tell you here and now that I will not ever, under any circumstances, be fitting a road tracking device to any vehicle in my fleet. No Sir. No way. Never. Not on your nellie, I'll go to prison first.