The other thing to remember though, is that they mainly operate in surveillance - which we are all well aware of. Surveillance, especially where government contracts are concerned, usually involve covert tactics. I'm sure any, if not all, government contracts they have received come with some sort of gag order. It's not very conducive to announce what they are planning to use to surveil along with specific benefits of the company they are using - it would tip off whoever they were trying to use it against.
Even assuming that there were no clauses in the contracts which prevented them from announcing the contracts, IMO it wouldn't be a very good business practice to announce every single one of them. Sure it would be good for stock PPS, but like I said - when you're in the surveillance business and you're in the habit of announcing contracts it basically ensures that no one who likes their privacy will do business with you.
All IMO of course, but I think we should keep in mind that the lack of PRs may be to ensure the survival of the company. I think that it may be more likely that we see evidence of contracts through financials than actual PR's regarding the specific contracts - with the exception of joint ventures from other manufacturers/think tanks.
Just my two cents.
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