Using filter query on HTTP delete

Is it a valid JSON API technique to delete a resource using the filter query?

DELETE /orders?filter[userId]=1

ONE user has MANY orders here.

Seems like that’s up to the application. If that’s a reasonable request, there’s no reason not to support it as far as I can tell. Whether the risks of deleting too much (think if there’s no filter provided) are too great is a question for the application designers.