They can only buy back stocks from people who want to sell them. The people who sell them do so because they believe it's a good deal. The process puts cash in the hands of those sellers, who can then go on to invest in something else, keeping the market more liquid rather than the first company sitting on cash reserves. The price of an individual stock is pretty much meaningless, you must multiply by the total number of stocks outstanding to determine the market cap. So it is not the buying back of stock that represents any fraud.

If there is any fraud, it would be having performance bonuses tied to individual stock price, rather than market cap. But blaming the buyback itself, is short-sighted.