Of course some people have made 1000% returns in a year. In most any given year, the top stock(s) will have risen in excess of 1000%. Company employees who happen to be holding the stock will have gained those returns.
But Position Traders question was "Do you think 1000% annual returns are possible". The word "return" was pluralized, so the question as I understood it was "is it possible to achieve 1000% returns on a regular basis".