Table 1. Cronbach alpha (overall)

Variable	Items	Item-test correlation	Item-rest correlation	Cronbach alpha	Overall
Online political participation	Frequency of writing original comments and replies on internet news/discussion boards over the past three months.	0.8423	0.7056	0.826	0.8622
	Frequency of scrapping posts on internet news/discussion boards over the past three months.	0.8399	0.7196	0.8213
	Frequency of online voting in the past three months.	0.8524	0.7310	0.8155
	Frequency of recommending and rating posts online over the past three months.	0.8337	0.6864	0.8347
Social media use	Frequency of writing posts and replies on social media in the past three months.	0.9393	0.8598	0.9077	0.9418
	Frequency of information sharing activities on social media in the past three months.	0.9510	0.8888	0.8845
	Frequency of recommending and rating posts on social media in the past three months.	0.9297	0.8436	0.9199
Private concerns	I am worried that people I do not know can see my online activities and obtain my personal information.	0.9284	0.8970	0.9592	0.9799
	I am worried that my personal information can remain on my old devices.	0.9128	0.8729	0.9617
	I am worried that, when I sign up for an online site, it asks for too much personal information.	0.9277	0.8937	0.9595
	I am worried that my online ID can be stolen.	0.9288	0.8957	0.9593
	I am generally concerned about my privacy when using the internet.	0.9429	0.9168	0.9571
	I am suspicious of people who do not reveal their identities online.	0.9105	0.8705	0.9619
	I am worried that people I do not know can see my online activities and obtain my personal information.	0.9284	0.8970	0.9592