By choosing a good quality service, you can make it easier to control how and when your real details reach other contacts.
Other organisations, like New Friends4U, are private sites, requiring security login, and we vet all registrations to weed out the more suspect applications.We also use an internal email system for initial contact, which is safer.In this situation New Friends4U acts as a forwarding address, so other users can contact you via the New Friends4U system, but don't get to see your real email address unless you give it to them directly.Again you can exercise some caution as to when you decide to do this. Passwords are there to protect your information, but it's surprising how many people don't take care of them, or pick passwords that a five year old could guess!If you think a password has been compromised, change it immediately, and if necessary inform the organisation who controls the system.
They should be able to shut down the login account and issue you with another login name and password.
When choosing passwords use a mixture of letters and numbers, upper case and lower case.
OK, it's more difficult to remember, but you finally memorised your telephone number didn't you?
I personally like inventing nonsense words with a few numbers used instead of vowels.
Nobody thinks exactly like I do (they're strange people if they do) therefore they're less likely to guess my invented words. It's fun trying to work out what a broldafrap could be used for. Some dating or friendship organisations are fairly relaxed about who they allow to join their community, with little vetting of registrations.
For these types of organisation, it might be wise to use an anonymous email account for initial contact, until you trust the people contacted well enough to divulge further information.