It's also come to light that the teams have been playing fast and loose with the recommended operating conditions of the tires

1. Running them at far lower pressures than Pirelli recommended (20psi front and 19psi rear), one team was reported to be running 15/14

2. Running 'left' tyres on the right and vice versa

3. running tyres at far higher camber than recommended

all of the above will give improved traction, and heating of they tyre, but also increase wear and make them more likely to puncture (and then fail if punctured)

now the FIA has made these recommended operating windows mandatory, together with the change to an inner Kevlar type rather than steel layer inside the tyre this should make them safe