Experts studying various types of mental stress in the UK have found that more and more people will experience varying degrees of discomfort after using the Internet. According to a sample survey of 10,000 people who regularly surf the Internet, the number of people who admit to feeling agitated and annoyed after surfing the Internet has reached one third, and 44% of Internet fans under the age of 20 admit to feeling irritable and nervous after going online. Psychologists believe that there is indeed some kind of "Internet Mania. ". According to the above information, which of the following are the least likely causes of "Internet Mania"? ['Due to the sharp increase in the number of Internet users and congested channels, if you want to access a relatively busy website, sometimes you have to wait a long time.', 'A variety of information can be accessed on the Internet, but often too much information will make people confused, lose confidence, and lose personal attention.', 'Although the use of the Internet is free in some countries, the online payment system is implemented in China, which has restricted the online time of Internet users.', 'Due to anonymity, Internet users are often treated rudely or received information spam by other Internet users.']