For the start the title sounds very stupid, does this mean that the author thinks that terrorists will start to use bitcoin when it becomes a little older? Perhaps terrorists are thinking about bitcoins same as about whine, leave it in the wine cellar for some time before we drink it
If someome read the report it will see that bitcoin is not main target here, NSA is developing tools for monitoring&tracking transaction for years, and probably all other security agencies working on it worldwide. They are more concerned about some new coins, which is a little harder to control.
However, the challenge posed by cryptocurrencies extends beyond Bitcoin. Many new cryptocurrencies have emerged in the past few years, including such alternative currencies (altcoins) as Omni Layer (MasterCoin), BlackCoin, and Monero, which are touted as more pri-vate and secure than Bitcoin. Zcash is another cryptocurrency that offers a higher degree of privacy and provides the potential ability to use and transfer currency offline, which could make it difficult for law enforcement to trace illicit transactions. Other cryptocurrencies have been proposed, including Hawk, which would allow fully private con-tracts and transactions on the Ethereum blockchain. Like Bitcoin, the Ethereum blockchain is a distributed computing platform and operat-ing system
It is also important to emphasize that this is an research that is more focused on the possible future abuse of cryptocurrency, perhaps because of the fact that there is currently no major terrorist organization in the world.
We see little current evidence of the adoption of cryptocurrencies by terrorist organizations or the moti-vation to do so, but that very well might change as countermeasures shut off funding and as the cryptocurrency technology changes.
https://www.rand.org/content/dam/rand/pubs/research_reports/RR3000/RR3026/RAND_RR3026.pdf 
