ga.js

// can use a random UUID for clientID
	// from: https://gist.github.com/jed/982883
	function uuid(a){return a?(a^Math.random()*16>>a/4).toString(16):([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,uuid)}


// stops analytics from working at all

	window['ga-disable-UA-XXXXX-Y'] = true;


// using ga.js 

	// anonymise IP address
	ga('set', 'anonymizeIp', true);

	// disable AdWords, DFP, retargeting, etc
	ga('set', 'allowAdFeatures', false);

	// ga clientID is still a unique identifier
	// so we either need to pass a fake clientID into the ga init call
	ga('create', 'UA-XXXXX-Y', { 'clientId': clientId });

	// or stop using any cookies at all
	ga('create', 'UA-XXXXX-Y', { storage: 'none' });

	// remove _gac_property-<id> (used in AdWords conversion tracking)
	ga('create', 'UA-XXXXX-Y', { storeGac: false });

	// set cookie expiration to zero turns _ga into a session cookie
	ga('create', 'UA-XXXXX-Y', { cookieExpires : 0 })


// using gtag.js

	// anonymise IP address
	gtag('config', 'UA-XXXXX-Y', { anonymize_ip: true });

	// disable AdWords, DFP, retargeting, etc
	gtag('config', 'UA-XXXXX-Y', { allow_display_features: false });

	// ga clientID is still a unique identifier
	// so we need to pass a fake clientID into the ga init call
	gtag('config', 'UA-XXXXX-Y', { user_id: clientId });

	// or stop using any cookies at all
	gtag('config', 'UA-XXXXX-Y', { storage: 'none' });

	// remove _gac_property-<id> (used in AdWords conversion tracking)
	gtag('config', 'UA-XXXXX-Y', { store_gac: false });

	// set cookie expiration to zero turns _ga into a session cookie
	gtag('config', 'UA-XXXXX-Y', { cookie_expires: 0 });