It is good to have more  contacts to demonstrate that your network large, but adding strangers into your network may do harm than good.

There are scammers in LinkedIn and these are what they are reported to do.

• Contact request. The scammer asks about your whereabout, job, and contact details.
• Suspicious links.
• Suspicious job offers.
• User claimed as recruiter. If so, always be vigilant to check the validity of job offer.
• Request for sensitive information, e.g. identification number and other personal details.
• Phishing
• Advance or commission fee.
• Others

If you do encounter such scams, please report to LinkedIn via (https://www.linkedin.com/help/linkedin/answer/56325/recognizing-and-reporting-scams?lang=en).

For a complete list of frauds or scams, visit Internet Crime Complaint Center (IC3, https://www.ic3.gov/preventiontips.aspx).