audiebam de: audio ex or ab is much more usual; cf. Att. 16.7.8.
alii facti sunt : this meaning of alius, which comes near that of diversus, belongs to colloquial Latin; cf. Plaut. Trin. 160 pro di immortales, verbis paucis quam cito aliunt fecisti me: alius ad te veneram (Bckel).
in eo, in his case or in their treatment of him.
abuti: explanatory of hoc.
libertate, freedom of speech; as repeated in eam, however, it means freedom in its widest sense.
providendumst: cf. persuasissimumst, Ep. XCVII.2n.
res se sic habet: a stereotyped introductory phrase, and therefore without influence upon the construction of the following sentence.
is bellum confecerit: the same opinion is expressed in nearly the same words in Fam. 10.13.2; 19.2.
hoc quam vim habeat: Cicero is probably hinting at the possible disloyalty of Lepidus, Pollio, and Plancus. It is necessary to crush Antony before any one of these men goes over to Antony's side. It is noticeable that although Brutus had written to Cicero pretty plainly of his suspicions of Lepidus in particular (cf. Ep. XCVII. 1), Cicero makes no reply upon this point, although he evidently shares the distrust which was felt by Brutus.