Surely you'd need to be a person of interest to have them process your data. The data is likely encrypted so how do they decrypt it? They can socially engineer a way in but does that work? Do people break down and give up their passcode?
Would they really process the data just because? It seems like a severe amount of data to process and evaluate. How much compute power is set aside for this and how much online storage is used? Do they use a cloud service for this?
It'd be interesting to hear from somebody in the know about what is they real can do and what is heresy.
In the past, a human was required for most policing operations. Economically, that meant you'd need to be a person of interest or at least incidentally connected to one to be subject to an investigation. It meant that judges and legislators could say stuff like "it's fine for the police to run arbitrarily license plates, that's public information" because running license plates meant there was a cop with a pad of paper walking through a parking lot, bringing the notes back to a clerk to manually tab through the registration files. Storing the data and processing it used to happen at human speed and cost on the order of $20/hr, assuming they weren't working overtime rates on nights, weekends, and holidays, now it runs at gigabits per second and costs $0.05/hr to run 24/7.
I'm not in the know, but I know that all the email content I've ever written is trivial to fit on a $50 hard drive, and with that I can search through 20 years in under 20 seconds.
It's not a question of "could they do it" but "would they do it", your answer to that question depends on social and political issues, not technology. It's why I prefer technical solutions like encryption to political problems like privacy.
To be honest, if your decryption process is "just" a passcode you "know" then you've already failed.
You could have a key and a passcode that relies on 10 steps (such as using a web service) that is reliable for you to know but not easy to "explain" how to obtain (and, as a bonus, easy enough to build in a dead man's switch, if I don't visit script.php within 24 hours the key is gone and even I can't decrypt now).
Would they really process the data just because? It seems like a severe amount of data to process and evaluate. How much compute power is set aside for this and how much online storage is used? Do they use a cloud service for this?
It'd be interesting to hear from somebody in the know about what is they real can do and what is heresy.