In Singapore, threatening to topple the government is a very serious matter that falls under several strict laws. The legal framework is designed to protect "national security" and "public order," and the authorities generally have a zero-tolerance policy for such rhetoric.
Here is a breakdown of the relevant laws:

Relevant Legislation
1. The Penal Code (Sections 121 and 121A)
The most severe charges fall under Offences against the State.
* Waging War: Under Section 121, anyone who wages war against the Government, or attempts or abets it, faces the death penalty or imprisonment for life.
* Offences against the President's Authority: Section 121A specifically covers those who plot to "overawe" the Government by force or show of force.
2. Internal Security Act (ISA)
The ISA allows the government to detain individuals without trial if they are deemed a threat to national security. This includes actions or threats that aim to overthrow the government or incite violence to destabilize the state.
3. Maintenance of Religious Harmony Act (MRHA)
If the threat to the government is made using religious platforms or involves inciting religious friction to cause political unrest, the MRHA can be invoked.
4. Protection from Harassment Act (POHA)
On a smaller scale, if a threat is made toward a specific public servant or government official that causes them alarm or distress, it can be prosecuted under POHA.
Consequences of Online Threats
It is a common misconception that "venting" or "trolling" online is protected. In Singapore, the Telecommunications Act and the Penal Code (concerning criminal intimidation) make it an offence to transmit messages that are known to be false or threatening.
If a Singaporean makes a public threat to topple the government:
* Investigation: The Internal Security Department (ISD) or the Police will likely launch an immediate investigation.
* Criminal Record: Convictions for offences against the State lead to heavy jail terms and a permanent criminal record.
* Social/Employment Impact: Due to the severity of these charges, it often results in immediate job termination and significant social fallout.
> Note: There is a clear legal distinction between constructive criticism (which is legal) and incitement or threats of violence (which are illegal and punishable by imprisonment).