<div class="no-copy">
    <p>You can't copy me.</p>
</div>

<div class="no-copy">
    .
    <p>But you can accidently copy me (in Safari/WebKit only, not Blink or Gecko) by selecting the periods around me.</p>
    .
</div>

<div class="all-copy">
  <p>One click selects all this.</p>
</div>

div {
  padding: 20px;
  margin: 20px;
  background: #eee;
}

.no-copy p {
  -webkit-user-select: none;  /* Chrome all / Safari all */
  -moz-user-select: none;     /* Firefox all */
  -ms-user-select: none;      /* IE 10+ */
  user-select: none;          /* Likely future */     
}

.all-copy p {  
  -webkit-user-select: all;  /* Chrome all / Safari all */
  -moz-user-select: all;     /* Firefox all */
  -ms-user-select: all;      /* IE 10+ */
  user-select: all;          /* Likely future */   
}