A common theme that is coming up among government officials and law enforcement is the idea of encryption backdoors to allow law enforcement to access your data. These are extremely dangerous and citizens should do all they can to prevent government from requiring these.
Yes, there will be information that the government may not be able to access in an investigation, on the other hand there is no way to guarantee that any backdoor will not be abused. In addition, due to how encryption works any form of government backdoor could be exploited by hackers. To allow the government to be able to do what they want will weaken the security of the data.
For these reasons, it is best to use open source encryption tools that have been independently verified by security professionals. When you rely on a corporation such as Facebook for the encryption you do not know what weaknesses there may be.
Make sure to reach out to your elected officials and let them know to protect our rights to encryption.