Is this a good-enough solution to creating directories?

I have a webform that needs to create a folder and copy some images to this folder. Basically, when the user uploads his images, the code will create a directory and upload these images there. This site is very public and it's free service.
In order to create these folders, I just created a container directory and gave the ASPNET account write premisssion, and each folder created by the visitor will be created under this directory.
Given these circumstances, is giving the ASPNET account write premisssion to this container directory a good-enough solution?
Thanks.
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