It "should" make the evidence excludable, but might not. Again, do some reading --- especially, if you can find them, law school articles --- on "Fruit of a poisonous tree".
Most obvious exception: if the actual introduced evidence comes from a drug deal that is done in plain site, where the accused is arrested with the money from a hand to hand or somesuch --- unlawful surveillance or not, the evidence from that arrest might not be excludable.
Most obvious exception: if the actual introduced evidence comes from a drug deal that is done in plain site, where the accused is arrested with the money from a hand to hand or somesuch --- unlawful surveillance or not, the evidence from that arrest might not be excludable.