The below code snippet explains how to disable or prevent cut, copy and paste operations in HTML and ASP.Net TextBox and TextArea using jQuery
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript">
        $(function () {
            $(".disable").bind("paste cut paste", function (e) {
                e.preventDefault();
                return false;
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    ASP.Net<br />
    <br />
    <asp:TextBox ID="TextBox2" runat="server" CssClass="disable"></asp:TextBox><br />
    <br />
    <asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine" CssClass="disable"></asp:TextBox><br />
    <br />
    <br />
    HTML<br />
    <br />
    <input type="text" class="disable" /><br />
    <br />
    <textarea class="disable" rows="5" cols="5"></textarea>
    </form>
</body>
</html>
 
Explanation:
In the above code snippet in the document ready event I have bind the event handler for cut, copy and paste operations in which I simply cancel the event.
 
Demo:
ASP.Net






HTML