what do you see?

So, general election fever is gripping the country at the moment, here in Japan. Rowdy campaign vans are out on the streets (they are allowed to use their megaphones from 8:30-5:30 apparently) being largely ignored by most of the populace as usual...but here's a quote I really don't get though, from Mainichi again:

"The opposition Democratic Party of Japan (DPJ) deleted a summary of a policy speech that leader Katsuya Okada made.....after the official campaign kicked off on Tuesday...
"...The law prohibits political parties and candidates from conducting campaigns on the Internet during official election campaign periods."

Why? Maybe I'm missing something here, but isn't the campaign period when you should be allowed to conduct campaigns? Or is the point that doing it on the Internet is not allowed, only from rowdy vans with megaphones which are largely ignored by the populace...?