well they would know, they've been spying on the ICC for a decade:
Exclusive: Investigation reveals how intelligence agencies tried to derail war crimes prosecution, with Netanyahu ‘obsessed’ with intercepts
www.theguardian.com
some choice quotes:
[...]
Israeli intelligence captured the communications of numerous ICC officials, including Khan and his predecessor as prosecutor, Fatou Bensouda, intercepting phone calls, messages, emails and documents.
The surveillance was ongoing in recent months, providing Israel's prime minister, Benjamin Netanyahu, with advance knowledge of the prosecutor's intentions. A recent intercepted communication suggested that Khan wanted to issue arrest warrants against Israelis but was under "tremendous pressure from the United States", according to a source familiar with its contents.
[...]
Five sources familiar with Israel's intelligence activities said it routinely spied on the phone calls made by Bensouda and her staff with Palestinians. Blocked by Israel from accessing Gaza and the West Bank, including East Jerusalem, the ICC was forced to conduct much of its research by telephone, which made it more susceptible to surveillance.
Thanks to their comprehensive access to Palestinian telecoms infrastructure, the sources said, intelligence operatives could capture the calls without installing spyware on the ICC official's devices.
"If Fatou Bensouda spoke to any person in the West Bank or Gaza, then that phone call would enter [intercept] systems," one source said. Another said there was no hesitation internally over spying on the prosecutor, adding: "With Bensouda, she's black and African, so who cares?"
[...]
They also sought to convince the prosecutor that, despite the Israeli military's highly questionable record of investigating wrongdoing in its ranks, it had robust procedures for holding its armed forces to account. This was a critical issue for Israel. A core ICC principle, known as complementarity, prevents the prosecutor from investigating or trying individuals if they are the subject of credible state-level investigations or criminal proceedings. Israeli surveillance operatives were asked to find out which specific incidents might form part of a future ICC prosecution, multiple sources said, in order to enable Israeli investigative bodies to "open investigations retroactively" in the same cases.
[...]
Multiple Israeli sources said the leadership of the IDF wanted military intelligence to join the effort, which was being led by other spy agencies, to ensure senior officers could be protected from charges. "We were told that senior officers are afraid to accept positions in the West Bank because they are afraid of being prosecuted in The Hague," one source recalled.