I can't speak for TLP, but here's my take on the process.. From what I've gathered, most of the stuff that TLP has posted has been info that can't be attributed to a single person. The Twins - Anyone involved in filming that scene. - Anyone involved in transporting those vehicles to the set Tilting Office Building - Anyone involved in filming that scene. Megatron returning - Anyone involved in filming that scene. - Production seeing head-on-a-stick props. Even then, you have any one of the above people who could talk to family members, friends, etc. Now, contrast this to your next point.. Often, there's not one script, especially with summer blockbusters. Scripts tend to be watermarked, or have little nuances used to identify a script if it leaks. Like say: SAM I don't get it Optimus! Why me?! SAM I don't understand Optimus! Why me?! SAM Why me?! I don't get it! SAM Why me? I don't get it!! ..or fake scenes between characters.. ..different locations mentioned.. ..objects.. ..name placeholders.. (which are a good indication of how current a draft might be.) With the way the last two leaked, security has to be even higher this time around. The only reason we've gotten so much this early is because of all the public stuff being filmed. Closed sets are easier to control -- look at Inception for an example of this. With all the information coming out, it's a little easier to sneak out info with all the other stories circulating, I'd imagine.