1. Private Security Firms:

After leaving office, many former high-profile individuals hire private security firms to handle their protection. Giuliani, as a lawyer and consultant with ongoing public appearances, particularly after his time as Donald Trump's lawyer, likely pays for a private security detail. This would come from his personal finances or through any funds tied to his ongoing business ventures.

2. Legal and Consulting Work:

Giuliani has been involved in various legal, consulting, and media-related projects since leaving public office, which may have provided the financial means to pay for private security. His association with powerful clients and high-stakes legal cases likely increased concerns about his personal safety, necessitating this kind of protection.

3. Fundraising and Donations:

In some cases, wealthy individuals or political allies may assist in funding security costs, especially if the person is involved in politically charged situations. Given Giuliani's controversial legal and political roles in recent years, it’s possible that supporters may have contributed to help cover security expenses.

4. Event-Related Security:

When Giuliani attends public or private events, the organizers of those events may also provide security for high-profile guests, which could supplement his personal security detail.

To summarize, the cost of Giuliani's current security detail is most likely borne by himself, his legal or consulting work, or through the assistance of wealthy allies or event hosts. There is no public information to suggest that his security is provided by the government.

(http://www.autoadmit.com/thread.php?thread_id=5606699&forum_id=2#48165207)