Were Harry's Temper Tantrums caused by Voldemort?

[BJHage]

No: HPFGUIDX 78384

One of the major points of OotP is Harry's behavior.  How he seems 
to have fits of temper and throws tantrums or screams at his friends 
at the slightest provocation.  I've been mulling this over and I 
have a few thoughts (yeah, I know... I have very few thoughts) 
anyways:

1) Throughout the entire series, Harry's scar has been a connection 
to Voldemort.  It hurts when Voldemort is feeling strong emotions, 
etc.

2)  The scar acts as some sort of link between Harry and Voldemort 
allowing either to view the actions and/or emotions of the other.

3)  Harry shows a LOT of temper in OotP.

4)  During every episode of Harry's temper that I could find in my 
sleep deprived scan of the book, Harry's outbursts are accompanied 
by a prickling sensation in his scar.

5)  This indicate involvement by Voldemort.

Therefore, isn't it likely that Harry's uncharacteristic fits of 
temper are not caused merely by the arrival of adolescence as we all 
seem to assume, but instead are caused by Voldemort using the link 
to either probe Harry's mind or even to insert these feelings of 
anger just as he inserts the dreams?  Perhaps, JKR has a more subtle 
scenario going than we suspect?  Perhaps, Snape's admonition to 
Harry about controlling his emotions is a key to controlling the 
intrusions?  Although, I must admit that I still find his statements 
highly ironic considering that Snape himself is totally unable to 
control his own emotions, unless you consider stifling all virtuous 
emotions and giving free reign to your venial ones control.

Can any of you good people out there show me where I've missed 
situations where Harry throws a tantrum that is not accompanied by 
activity from his scar?  Perhaps I am just missing them.

BJH