There is a legality issue whenever you release any animal into the wild. In the state of Virginia, the law states blankly that no animal can be released into the environment. However, I personally would have no problems with releasing frogs back into the same place where you found them. Release them soon, especially if it is getting cold in your area.
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...the oldest task in human history: to live on a piece of land without spoiling it."
Aldo Leopold (1938)
"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
Calvin and Hobbes