Hot-air balloons move with the wind. If this was not the case the balloon would land on th launch site! During the flight passengers (although not the pilot) are completely unaware of the wind conditions because they are moving at precisely the same speed as the wind, and also in the same direction.
Upon landing, the basket makes contact with the ground and wants to stop but the envelope continues to move with the wind. In all but the most calm conditions this inevitably leads to the balloon heeling over and the basket being pulled along the ground as the pilot struggles to deflate the envelope. In some cases the basket may tip on its side and be dragged for some distance before finally coming to a stop. This is known as a "sports landing".
The pilot should warn the passengers of any possible landing hazards, and may ask them to crouch down so their heads are below the top of the basket and hold on tightly to the handles provide for the purpose. Photographers also have to retain a firm grasp on their equipment at this time. Ideally all equipment should be packed away and protected in some way.
The pilot will advise when it is safe to leave the basket - don't try to get out before this advice is given because the reduced weight of the basket may cause the balloon to rise back in to the air. A ground crew normally arrives at the landing site within a short period of the landing, and will immediately begin the process of securing the basket and deflating the envelope.