Gadol
““Gadolhadorah”s Torah Insights” ‘copyrighted”
Well, yours not LOL.
As per Halacha it is muttar. If you give a Shiur for the public and someone goes and repeats it or even quotes you fully in a sefer. No doubt – you can not claim it is MY Torah and no one is to repeat it . Even published sforim are not so simple that anyone can claim it as Copyright after you covered all your expense.
If you ever looked into the approbations of any old sefer you will see, one of the things mentioned is a prohibition of reprinting the sefer after a certain time frame or, until the author makes his profit etc. No need to say, if there is no profit involved it should be allowed.