Harassing text
I am receiving harassing texts from people hiding their identity
iPhone 6s, iOS 11.0.3
If these are text messages (SMS) report them to your carrier. If it's an iMessage, report it by sending it in an email to imessage.spam@icloud.com.
If you're not sure which it is, see: About iMessage and SMS/MMS - Apple Support.
This may also help: Block phone numbers and contacts on your iPhone, iPad or iPod Touch - Apple Support.