Ok well not steal but if you have HUGE patches and fileds of normal (not hybrid) flowers ad you don't mind people taking it can I take a few bunches :c My town has so little flowers...
You can get a bunch of flowers from any island mini-game, especially the Gardening Tour. (When you're about to plant the last flower, grab as many as you can carry.)
Tours are an awesome way to gather flowers! Especially the butterfly and gardening tours since you can get the "new" flowers on those minigames...I believe they are lilies and violets.