SharePoint 2010: Limit the storage limit for already created Personal Sites

Hi,

I have a SP 2010 portal, there are many users using this site, and hence there are a lot of Personal sites created for all the users.

It is observed that people use their personal site to dump the data. i want to restrict the storage limit on the personal sites, so that no one should be able to add data.

I read some articles which said that we can restrict storage limit for new personal sites but not for already created site collections. If it has to be done for already created personal sites, then, it would be done manually for all the site collections. But in my case manual job is not possible.

What can be done to get the desired result?

Thanks in advance.

Regards, Priyanka Makkar