BBC.COM - Mar 3 - Many dating sites and apps issue guidelines, such as never to give out personal information and to watch out for odd language in messages or personal profiles, for example. Many insist they apply security measures, but won't reveal what systems they use. A spokesman for Match.com said: "We have a dedicated team who monitor security on the site, through both up-to-date technology and human checks. "Bigger organizations will use a variety of datasets as part of their counter-fraud solutions," says Andrew McClelland, CEO of the Online Dating Association (ODA). Some experts believe dating sites could be doing more to analyze the language people use. Last year a group of researchers at London's City University compared tens of thousands of emails pre-identified as lies with those known to be truthful. The algorithm analyzed their word use, structure and context for linguistic differences. Liars cannot generate deceptive emails from actual memory so they avoid spontaneity to evade detection. Algorithms can pick up on these traits.