However, there's certainly secondary and tertiary affects. The government can already get your email with warrants and other compulsory legal processes for other kinds of data: so if you're sending your private keys with nothing more than your email service's encryption, yeah you're screwed if the government wants to eventually seize your Bitcoin pursuant to valid civil or criminal forfeiture order.
why you should do something like that?, just do a regular spent of your coin, if you want to send an amount of bitcoin or whatever
in the future if regulation will be too tough, we will use subterfuge like monero or we can create our own monero clone and no one will know about it
*shrugs*
People are stupid. Obviously no one should be storing their private keys in an unencrypted manner or sending them through unencrypted channels. But no doubt some people do. If you do that, the government, right now, can easily get that information through legal channels with normal legal process.