I wish it surprised me that this thread is full of people who insist that this isn't a major issue and that no action should be taken. (Ugh, "moderates")
Step 1: Identify as many offenders as possible (using Communism's original catfish method), and build a list. Do nothing with this list until it is "large enough."
Step 2: Ban the users from the list from the site.
(optional further action)
Step 3: Repeat steps 1 and 2 for the remaining offenders (who may need a few days to figure out how to evade the ban) until satisfied.
Step 4: Delete Flirt.
Step 5: Establish a chat (ex. "Dating") with moderators.