will excuse a violence response by the police:
i.e. will provide the police with a dishonest argument to show that their violence is necessary
have taken advantage of:
if you take advantage of something you use it to your benefit. We often speak, for example, of taking advantage of an opportunity.
social networking sites:
A website where people interact with one another, like Facebook, Twitter, or Linkedin
“allusion” is the noun form of the verb “allude.” If you allude to something, you refer to it or suggest a connection to it without actually mentioning it.
a nursery rhyme is a traditional (and often very old) poem for young children. A nursery is a room where children play, sleep etc. The word “rhyme” in this context has the same meaning as “poem.” The word is more commonly used as a verb when speaking of two words which rhyme because they have a similar final sound (e.g. “food” and “rude.”)