Never mind whether your date is smart or good-looking. How do you know you aren’t flirting with a felon?

For a small fee, a nascent crop of companies wants to help you find out by running background checks on the potential flames you encounter on Match.com, eHarmony or any of the nation’s nearly 1,500 dating Web sites.

At the same time, at least two states, New York and New Jersey, have begun regulating Internet dating sites, and legal experts say they believe changes to the liability laws that protect such sites are on the horizon.

And you thought your mother was the only one who wanted to vet your love life.

The focus on background screenings comes as some 20 million Americans are using dating sites, more than double the number five years ago, according to the market research firm IBISWorld. While they are finding casual dates and even love, they are also encountering married people pretending to be single or, worse, sexual predators and convicted felons.