Your focus on pedantry belies a lack of understanding of the underlying topic. The overall strategy of "pump and dump" is commonplace and results in little chance of a felony conviction. The basic idea is you buy a stock, you talk it up, and you quickly sell having made money even though the prospects and fundamentals of that company did not change during the time you owned it. This is certainly what Icahn is trying to do, otherwise he wouldn't be wasting his time on twitter. This is also practiced by analysts and high-profile commentators all the time (Cramer has admitted to doing it himself at various points in his life and has pointed out many other doing the same).
Only in certain very specific circumstances is it a felony, such as if you fabricate the information you are pumping with, promise prospective investors returns (such as by certain spammers), fail to disclose your interests, etc. Even then, the chance of getting caught is pretty close to zero. Calling someone a pump and dump does not mean you are calling them a felon, but it does mean that you are calling them a leach- someone who is trying to make money on financial transactions while no underlying value has been created.
