As of November 2015, you can legally watch the 2004 comedy "Mean Girls" online by streaming it using Netflix, iTunes, Vudu or the PlayStation Store. Watching "Mean Girls" via Netflix requires a monthly subscription.
As of November 2015, renting a digital version of "Mean Girls" online costs $2.99 on iTunes, Vudu and the PlayStation Store. Purchasing a digital version of the film costs $9.99 on iTunes and Vudu. It is not available to purchase through the PlayStation Store.
To watch it via Netflix, you must be a monthly subscriber to the service, which costs between $7.99 and $11.99, depending on the plan you choose.