I haven't gotten these on twitter, but this happens on facebook almost with every sweeps I enter. I know on fb you can hover over the icon of the person who replied and it will tell details. So if I entered a contest from lets say jackery and the icon shows the jackery icon, but says business is real estate than I know it is a clone. Also, it will say how many followers. Obviously, if there is 1 to a very small amount of followers than it is a clone icon. One of the reason I hate social media contests, but they are becoming more and more popular with sponsers.