Reading Acts 7 again. Stephen's speech is a rhetorical and strategic masterpiece. Early on, he keeps throwing in these hints that the Sanhedrin did to Jesus what Israel did to Moses, all while recounting Israel's history in detail, thus proving he is "a good Jew." He thus gets them to listen before turning up the heat and making it more clear: Israel rejected Moses, and Moses said God would send a prophet like Moses, and that we were to listen to Him.
His last short section is in-your-face and inflammatory. Stiff-necked! Uncircumcised! Sons of those who murdered the prophets! (Who foretold the One you all killed!) You have the law, but you don't keep it. This last one was probably the worst, as their greatest point of pride was that they kept the law of Moses.