When adverticing just started to became regularity, it already had drawbacks. So there is the argument that the advertisment which targeted for children audience should be prohibited. I totally agree with this statement.
To begin with, the most popular problem that caused by advirtisment is propaganda, does not matter for who it was directed. Huge amount of innocent citizens under the influence of advertising companies start to consume a lot of misinformation and often turning against the governence or authority. This problems chases not only adults, but even children and teenagers. Kids firstly recieve information without parents observe from the TV shows and frequently become victim of harmful marketing. For instance, about 10 years ago, when advertisments was less streaked by TV companies, it is easy to see propaganda like romanticizing robbers or thieves just for sales of this like equipment.
However, today we have a lot of educational and beneficial advertisment provided by goverment, i believe that it is not realy safety for children. In another words marketing companies not under total control and it can be really dangerous for young generation which not fully developed own opinion yet. In addition, advertisment that attracts to play more or this sort of marketing may cause low educational or academic interest in next generations. For example, today there is tendency of adverticing mobile or computer games in mass media, that caused boom in gaming attendance level that doubled for last 3 years. Experts assume that this trend becomes crucial for mark of primary and middle school students.
To sum up, althought goverment makes an effort to clean mass media from propaganda and harmful advertisment, it always takes place in some measure. It really hard to conrol all sort of media that affect on kids. Moreover, even the video game adverticing might be not that good for children.