They almost immediately started burning documents[1].
> "All I know, it's illegal to have open burning in the city of Houston like that," Houston Fire Chief Samuel Peña said.
[1]: https://www.chron.com/houston/article/U-S-orders-Chinese-Con...
> "All I know, it's illegal to have open burning in the city of Houston like that," Houston Fire Chief Samuel Peña said.
[1]: https://www.chron.com/houston/article/U-S-orders-Chinese-Con...
The U.S used shredder to destroy document in Iran in 70s but Iranians were able to piece back the document to get intel from it so I guess the intelligence community learned a lesson there.
[1]: https://www.msnbc.com/all-in/watch/why-was-the-russian-consu...
If the shredder shreds with 1mm particles, it will be pretty much impossible to piece it together and it will depend on how each page mixes with other particles. Even if the particle size is 100mm, if you throw those pieces in a pile of 500 tons of paper, and shuffle it sufficiently, then it will be impossible to piece together the original source.
https://en.m.wikipedia.org/wiki/DARPA_Shredder_Challenge_201...