Can a creature with summoning sickness be targeted?
Yes you can target a creature with Summoning Sickness. Summoning Sickness only prevents creatures that you haven't controlled since the start of your turn from attacking or using activated abilities with {T} (Tap) or {Q} (Untap) in their activation cost.


  *Summoning Sickness Rule *
  
  Informal term for a player’s inability to attack with a creature or to activate its abilities that include the tap symbol or the untap symbol unless the creature has been under that player’s control since the beginning of that player’s most recent turn. See rule 302.6. See also Haste.
  
  302.6. A creature’s activated ability with the tap symbol or the untap symbol in its activation cost can’t be activated unless the creature has been under its controller’s control continuously since his or her most recent turn began. A creature can’t attack unless it has been under its controller’s control continuously since his or her most recent turn began. This rule is informally called the “summoning sickness” rule.
  
  107.6. The untap symbol is {Q}. The untap symbol in an activation cost means “Untap this permanent.” A permanent that’s already untapped can’t be untapped again to pay the cost. A creature’s activated ability with the untap symbol in its activation cost can’t be activated unless the creature has been under its controller’s control continuously since his or her most recent turn began. See rule 302.6.