Safety
Your location stays yours. Personal posts (meetups, walks, dates, lost pets) show only an approximate area on the map. Garage sales and markets can show an exact address only if you choose to.
Messages stay on the site. You can talk without sharing your phone number or e-mail. Messages that look like scams, threats or sexual harassment are hidden automatically and the sender is restricted.
Meeting someone? 1. Meet in a busy public place, in daylight if you can. 2. Tell a friend where and with whom you meet; share your live location with them. 3. Arrange your own transport and keep your phone charged. 4. Leave at once if something feels wrong.
Buying or selling? - Look at the item before you pay. Pay in person. - Never pay a deposit or "delivery fee" in advance to a stranger. - Never send codes from SMS, bank details or photos of documents.
Block and report. Every profile, post and message has "Block" and "Report". Blocked people can no longer write to you.
In an emergency call your local emergency number (112 in Europe, 911 in North America).