I can sea there's a new dating lure floating around the internet and it seems to have people hooked. if you haven't picked up on the name of this dating technique from the multiple horrendous puns in the first sentence, its called Fishing...
fishing is where the keen dater sends out the same message to multiple "fish" and see who takes the bait. the bait may be a generic message as simple as "hey, hows it going?" or "what are you up to tonight" fishing may include the use of the sly emoji too. Seems like a good idea if you are wanting to keep your options open, but i'm sure its pretty stink if your one of the fish.
Ways to keep an eye out for yourself and avoid being one of the fish is to avoid generic, or random messages from people that you weren't expecting to hear from. If the message seems like it could have been copied to multiple people there's a good chance you are being treated as a sea specimen. If you do take the bait and your potential flirter takes a while to respond, this could also be a sign that you are dealing with a fisherman.
Technically there's nothing wrong with casting out a wide net on dating apps or social media, but no one wants to be a side option. If the person your talking to is a fisherman, they probably aren't worth your time and commitment.