OOP: Protection... mistake or foreboding?

[Maria]

No: HPFGUIDX 64811

I Think I have discovered a mistake with this protection thing... 

Harry is at the Dursleys because Petunia can protect Harry, since she 
is of blood relation to Lily. But Voldemort now Has Harry's blood and 
protection in him... 

Since the Dark Lord can touch him and so forth, wouldn't this allow 
Voldemort to walk up Privet Drive and into the Durlseys home and kill 
them and Harry??? 

Or maybe this is not a mistake in OOTP and Voldemort will realise 
this in the next books and use it to his advantage... attack Harry at 
his most vulnerable. 

What do you guys think?

Maria.
www.geocities.com/queen_amidala/