Facebook Marketplace Scam Flag Highlighter

WHAT IT DOES

Facebook Marketplace Scam Flag Highlighter scans Marketplace listings and applies intelligent heuristics to flag potential scams. It analyzes each listing for multiple scam indicators: prices significantly below market average, newly created seller accounts, lack of profile picture, generic/vague descriptions, urgent pressure language, and requests for payment outside the platform. Each listing receives a color-coded risk level—red for high-risk scams, yellow for caution, green for low-risk. A summary panel shows the total listings scanned, breakdown by risk level, and a list of flagged listings with specific scam indicators. You can copy the full scam report as text for sharing or further investigation. This helps you shop safely on Marketplace by identifying suspicious listings before you engage with sellers.

WHERE IT RUNS

This script runs on Facebook Marketplace pages (*.facebook.com/*). It operates entirely within your browser tab, reading the page's DOM to locate listing cards, seller information, prices, and descriptions. The script cannot access other tabs, your browsing history, bookmarks, downloads, or any data outside the current page. All settings—including price threshold, flag new accounts, flag no profile pic, flag generic descriptions, flag urgent language, and auto-analyze preference—are stored locally using GM_setValue and never transmitted anywhere.

HOW TO USE

After installing with the BotGentz extension, the script automatically scans Marketplace listings you view (if auto-analyze is enabled). Each listing card is highlighted with a colored border and background: red for high-risk, yellow for caution, green for low-risk. A risk badge appears on each listing showing the risk level, and hovering over any listing shows detailed flag information. The panel summary shows total listings, high/medium/low risk counts, and a list of high-risk listings with their flags. Customize which scam indicators to flag: new accounts, no profile picture, generic descriptions, urgent language, and adjust the price threshold. Click "Copy Scam Report" to export a complete report to your clipboard.

THE REAL MECHANISM

The script detects Facebook Marketplace listing cards using multiple selectors (.marketplace-listing-card, .listing-card, .marketplace-item, [data-testid="marketplace-listing"]) to handle different Facebook UI versions. For each listing, it extracts the title, price, description, seller name, and checks for profile picture presence. New account indicators are detected by scanning for "Joined recently" text or new-account class names. The flagging system uses a multi-stage heuristic analysis: the urgent language detector checks against a list of 30+ scammy phrases ("urgent," "cash only," "wire transfer," "gift card"), the generic description detector counts overused phrases like "brand new," "mint condition," and "perfect condition," and the price checker flags suspiciously low prices for expensive item categories. Each flag adds to the risk score, with 3+ flags triggering a high-risk classification. All listings are rendered with color-coded borders and badges, and the summary panel aggregates statistics across all listings found on the page. All DOM manipulation uses safe methods with no innerHTML from untrusted content.

THE PANEL

The Scam Flag panel is a BGPanel component that you can drag anywhere on your screen by its header. It snaps to the nearest edge when released, keeping your workspace organized. The panel collapses to a small bubble showing only the emoji icon when minimised—click to expand it again. You can resize the panel horizontally to see more of the scam report. Press the Escape key to collapse the panel instantly. Your panel position and size are saved per-site.

PLEASE NOTE

This script requires the free BotGentz browser extension to function. Facebook frequently updates its Marketplace UI, which may change class names, data-testid attributes, and DOM structure—the script may require updates to maintain compatibility. The scam detection uses heuristics and is not 100% accurate; some legitimate listings may be flagged as suspicious, and some scams may not be detected. Always exercise caution and common sense when dealing with Marketplace transactions. The price threshold is a simplified heuristic and may not be accurate for all item categories. The script never reads or writes password fields, hidden inputs, or file inputs. It stores only your price threshold, flag new accounts preference, flag no profile pic preference, flag generic descriptions preference, flag urgent language preference, and auto-analyze preference locally. No listing data, user information, or personal information is ever collected, transmitted, or shared.