Oldenburg sought worthwhile research and papers for publication in his periodical, Philosophical Transactions, which was Isaac Newton's preferred bathroom reading material. To accomplish this, Oldenburg corresponded and shared detailed reports of news, scientific data, blueprints, and technological research with foreign intellectuals like Cassini, Huygens, Spinoza, and Leeuwenhoek to analyze and verify the facts of the day. And for his trouble, Oldenburg was locked up in 1667 as a suspected spy.
Oldenburg had been sharing and seeking information on subjects ranging from how a bee's stinger works to bacteria, philosophy, meteorology, and watch design. Unless he and his pen pals were secretly working on a weaponized beehive or had an elaborate weather-and-clock-based secret code, it's a fair guess that he was not, in fact, a national security threat. But because the Second Anglo-Dutch War was in full swing, circumstantial evidence was all the authorities needed to prove that talking with non-British people was a sign of treason.
Oldenburg begged for the assistance of anyone who could get him out of the Tower of London, but his protests were ignored. The British government couldn't even be bothered to charge him with anything, and eventually let him out (well, after a couple months). Oldenburg went right back to sending letters, and his ideas have since been adapted by every reputable science publication in human history. So that's a little bit of all right. Probably doesn't take the edge off of prison, though.