Bungie resides in Washington State and WA has laws regarding gaming. Bungie must be licensed with the gaming commission as they are conducting a lottery (offering the possibility of an unspecified prize for MONEY). They do list all the possible prizes at Eververse, however, they don't give you the odds of winning(reguired by law). Aside from irresponsibly, possibly illegally offering this lottery to miners they also admitted to rigging a portion of the lottery games to not give what was promised(in writing). That, according to WA state law is fraud. And that is why you heard Bungie respond, as soon as the fraud was officially pointed out, "the xp bonus wasn't working as intended" and they were correcting the problem. And that is also how they're trying to dodge their possible violation of Washington's gambling laws.