Except we're not talking about "soft guidelines" or simple recommendations but actual laws:
* Executive Order 13526 - https://www.whitehouse.gov/the-press-office/executive-order-...
* 18 U.S. Code § 793 - https://www.law.cornell.edu/uscode/text/18/793
* The 2009 Federal Records Act
* (probably) The Freedom of Information Act
in addition to a classified information non-disclosure agreement:
* https://foia.state.gov/searchapp/DOCUMENTS/HRC_NDAS/1/DOC_0C...
http://www.govexec.com/insights/state-internal-workplace-com...
https://www.washingtonpost.com/politics/clintons-experience-...
So, if it's some poor functionary at the bottom of state, his ass is out on the street if his phone comes into the classified area. Some spillage can sometimes be met with a slap on the wrist, but there's very little chance that you'll get off easy after bringing a microphone/GPS/camera/networked/mass storage device in to secure areas.
Most of the NSA people are free to buy Huawei Nexus 6p (although I'll bet there's some statistically significant disinclination) because their phones should never be interfacing with any of the information they use in their work.
I absolutely agree that protecting classified information by whatever rules are in place is of primary importance.
However, we've all seen dysfunctional organizations. So I'm also sympathetic to someone trying to get work done and ignoring soft guidelines in favor of an institutionally accepted interpretation that's conducive to accomplishing the job. And unsympathetic to telling someone at the time "we really should do that, but everyone does this" and than raking them over the coals from a future armchair that we were shocked (!) that they didn't following all guidelines.
Show me a successful, highly-productive individual's records and I'll show you somewhere they forgot to cross a t.