This might not be possible to circumvent with a 'hack'. What this is, is the digital equivalent to the Newspapers and Printing Presses Act [1] (which is part of the "regulatory framework" for traditional news platforms that is cited in the article). It's a legal/regulatory thing, not a software thing.

Put simply, yes, this is a way for the government to regulate major news organisations that are regularly visited by Singapore IP addresses, and that write Singapore-related news articles at least once a week. (The MDA seems to consider online services regulated under the Broadcasting Act. [2]) So:

(1) they ask these big companies to put up a $50,000 bond; (2) big company's employees may feel the need to self-censor, especially if there's a possibility that they might lose their jobs and much more if they're the ones who write the articles causing big company to lose part of their performance bond; (3) they achieve some degree of control over news and media organisations with an incorporated entity in Singapore, since those are the easiest to regulate.

The way I see it, it's really hard to define what Singapore-related news is, and 50,000 unique IPs is roughly 0.08% of the IPv4 addresses allocated to Singapore [3]. Considering that most consumer internet services here use dynamic IP allocation, it's not a high threshold to hit.

(I'm not a lawyer. I'm also very interested in hearing everyone else's take on this.)

[1] http://statutes.agc.gov.sg/aol/search/display/view.w3p;page=...

[2] http://statutes.agc.gov.sg/aol/search/display/view.w3p;page=...

[3] data from http://www.nirsoft.net/countryip/sg.html