Ticketmaster Touts!

I am not a major U2 fan, but consider their Joshua Tree LP to be a classic.  I was keen to see them perform their 30th anniversary tour.  I logged on to the official ticket seller just as tickets went on sale.  However, for some reason, all tickets had been sold ... but they could still sell me tickets that hadn't been sold (or maybe they had been sold - smoke and mirrors) at vastly inflated prices via their associated site.  Isn't this illegal?  I will not be going,