Cic. Q.fr. 3.4.1
Two men of praetorian rank were on the panel—Domitius Calvinus, who voted for acquittal so openly that everybody could see; and Cato, who, as soon as the voting tablets had been counted, withdrew from the ring of people, and was the first to tell Pompey the news.
duo praetorii sederunt, Domitius Calvinus (is aperte absolvit ut omnes viderent) et Cato (is diribitis tabellis de circulo se subduxit et Pompeio primus nuntiavit).
In my book there is a whole section in chapter 4 on the secret ballot and voting tablets on coins. Those used in the law courts had two choices: A(bsolvo) or C(ondemno), ‘I absolve’ or ‘I condemn’, or L(ibero) or D(amno), ‘I free’ or ‘I sentence’. What I like about the above passage is that it nicely shows how followers of Pompey the would be autocrat are undermining the anonymity of the ballot to show their partisanship AND that Cicero’s words help confirm the interpretation of what we see on ballots on at least one coin (RRC 428/2) dating to just the year before.

This post relates to the content of the previous one as well.